The United States has expanded its controversial travel ban to include people from North Korea, Venezuela and Chad.
The White House said the restrictions follow a review of information sharing by foreign governments.
Donald Trump issued a presidential proclamation late on Sunday.
"Making America safe is my number one priority. We will not admit those into our country we cannot safely vet," Mr Trump said.
The restrictions on Venezuelans apply only to government officials and their family members.
The three new countries join five others from Mr Trump's original travel ban: Iran, Libya, Syria, Yemen, and Somalia. But the new proclamation removed restrictions that were placed on Sudan.
Mr Trump's original ban was highly controversial, as it affected six majority-Muslim countries, and was widely labelled a "Muslim ban".
It was subject to a range of legal challenges and the subject of several large-scale protests, and is due to be considered by the US Supreme Court in October, having been partly reinstated in July.
The American Civil Liberties Union rights group said the addition of the new countries "doesn't obfuscate the real fact that the administration's order is still a Muslim ban".
It is not yet clear how the president's new proclamation, which changes several key elements, will affect that legal challenge.
The addition of North Korea and Venezuela now means not all nations on the list are majority-Muslim.
The criteria for the new ban list is now based on vetting procedures and co-operation, and the restrictions have now been "tailored" on a country-by-country basis:
North Korea has fired a missile over northern Japan in a move Japanese Prime Minister Shinzo Abe called an "unprecedented" threat to his country.
The missile, launched early on Tuesday Korean time, flew over Hokkaido island before crashing into the sea.
The UN Security Council is expected to hold an emergency meeting in response.
North Korea has conducted a flurry of missile tests recently, but this is the first time it has fired what is thought to be a ballistic weapon over Japan.
On the two previous occasions its rockets crossed Japan - in 1998 and 2009 - North Korea said they were for satellite launch vehicles, not weapons.
The BBC's Rupert Wingfield-Hayes in Tokyo says this latest launch appears to be the first of a missile powerful enough to potentially carry a nuclear warhead.
The South Korean military said the missile was fired eastward just before 06:00 local time (21:00 GMT) from near the North's capital, Pyongyang - which is rare.
Early analysis of the launch suggests the missile:
No effort was made by the Japanese to shoot down the missile but it issued a safety warning telling citizens in Hokkaido to take shelter in "a sturdy building or basement".
US and Japanese forces are currently taking part in training drills in Hokkaido.
South Korean President Moon Jae-in ordered a show of "overwhelming" force in response to the launch. Four South Korean jets staged a live bombing drill on Tuesday.
Mr Abe said he had spoken to US President Donald Trump and that both agreed to increase pressure on North Korea.
North Korea has said it is considering carrying out missile strikes on the US Pacific territory of Guam.
The report in state media, quoting an earlier military statement, came hours after President Donald Trump threatened North Korea with "fire and fury".
The North's official news agency said it was considering a plan to fire medium-to-long-range rockets at Guam, where US strategic bombers are based.
The exchanges mark a sharp rise in rhetoric between the two countries.
The UN recently approved further economic sanctions on North Korea, which Pyongyang said were a "violent violation of our sovereignty", warning the US would "pay a price".
On Wednesday, the official KCNA news agency said North Korea was "carefully examining the operational plan for making an enveloping fire at the areas around Guam" using its domestically made medium-to-long-range Hwasong-12 missiles.
The news agency reported a military statement issued on Tuesday, which probably came in response to US military drills in Guam.
In a message to the public, the governor of Guam Eddie Baza Calvo said there was currently "no threat" to the island and the Marianas archipelago, but that Guam was "prepared for any eventuality".
North Korea's statement is the latest stage in a heating up of rhetoric and tension.
Pyongyang, which has tested nuclear devices five times, launched two intercontinental ballistic missiles (ICBM) in July, claiming it now had the ability to hit the mainland US.
On Tuesday, media reports in the US claimed the North had achieved its goal of making a nuclear warhead small enough to fit inside its missiles.
While not confirmed, this was seen as one of the last obstacles to North Korea being a fully nuclear armed state.
A report in the Washington Post, citing US intelligence officials, suggested North Korea is developing nuclear weapons capable of hitting the US at a much faster rate than expected.
A Japanese government defence white paper also said the weapons programme had "advanced considerably" and that North Korea possibly now had nuclear weapons.
In response, President Trump warned North Korea to stop threatening the US, saying they would be "met with fire and fury like the world has never seen".
However veteran US Senator John McCain was sceptical about Mr Trump's statement, saying he was "not sure that President Trump is ready to act".
The US government is not seeking a regime change in North Korea, the secretary of state says, amid tensions over Pyongyang's weapons programme.
"We're not your enemy," Rex Tillerson said, adding that the US wanted a dialogue at some point.
But a Republican senator said President Donald Trump had told him there would be a war with North Korea if its missile programme continued.
Pyongyang claimed its latest missile could hit the US west coast.
The second test of an intercontinental ballistic missile (ICBM) on Friday, celebrated by North Korean leader Kim Jong-un, was the latest to be conducted in defiance of a United Nations ban.
"We do not seek a regime change, we do not seek the collapse of the regime, we do not seek an accelerated reunification of the peninsula, we do not seek an excuse to send our military north of the 38th parallel," said Mr Tillerson, referring to the border between the Koreas.
"We're not your enemy, we're not your threat but you're presenting an unacceptable threat to us and we have to respond."
President Trump has repeatedly criticised China, which shares a land border with North Korea and is its closest economic ally, for not doing enough to stop Pyongyang's weapons programme.
However, Mr Tillerson took a more diplomatic approach, saying that "only the North Koreans are to blame for this situation".
"But," he added, "we do believe China has a special and unique relationship, because of this significant economic activity, to influence the North Korean regime in ways that no one else can."
In a separate development, Republican Senator Lindsey Graham said that Mr Trump told him that there would be a military conflict between the two countries if Pyongyang continued with its aim to develop a missile programme with the US in its range.
"There will be a war with North Korea over their missile programme if they continue to try to hit America with an ICBM.
"He [Trump] has told me that, I believe him, and if I were China I would believe him too, and do something about it," he said in an interview with NBC's Today programme.
Mr Graham added: "If there's going to be a war... it will be over there. If thousands die, they're going to die over there. They're not going to die here. And he [Trump] has told me that to my face."
South Korea has proposed holding military talks with the North, after weeks of heightened tension following Pyongyang's long-range missile test.
If they were to go ahead, they would be the first high-level talks since 2015.
A senior official said talks should aim to stop "all hostile activities that raise military tension" at the fortified border between the Koreas.
South Korea's President Moon Jae-in has long signalled he wants closer engagement with the North.
North Korea has not responded to the South's proposal yet.
In a recent speech in Berlin, Mr Moon said dialogue with the North was more pressing than ever and called for a peace treaty to be signed.
He said such dialogue was crucial for those who seek the end of Pyongyang's nuclear weapons programme.
However, the North's frequent missile tests, including the most recent one of an intercontinental ballistic missile, are in consistent violation of UN resolutions and have alarmed its neighbours and the US.
South Korea's Vice Defence Minister Suh Choo-suk told a media briefing that talks could be held at Tongilgak, a North Korean building in the Panmunjom compound in the demilitarised zone between the two countries, which was used to host previous talks.
He proposed that the talks be held on 21 July, and said: "We expect a positive response from the North."
South Korea's Unification Minister Cho Myoung-gyon also urged the restoration of communication hotlines between the two Koreas, cut last year after a North Korean nuclear test.
The BBC's Karen Allen in Seoul says the ultimate aim of these talks would be to end the military confrontation that has dominated relations between the two Koreas for decades.
But it could begin with confidence-building measures such as ending the infamous loudspeaker propaganda broadcasts along the border, she says.
The Red Cross and the government have also proposed a separate meeting, aimed at discussing how to hold reunions of families separated by the Korean War, which ended in 1953.
But analysts say these could be highly fraught with Pyongyang still angry at the South's unwillingness to repatriate high-profile defectors.