For Mr. Trump, whose efforts on health care, infrastructure improvements and tax reform are gaining little steam, the new order is a third attempt to make good on his campaign promise to respond to terrorist threats by tightening entry at the nation’s borders. In December 2015, he called for a complete ban on travel to the United States by Muslims “until our country’s representatives can figure out what the hell is going on,” though he later denied that he had sought a religious test on travel.
Officials described the new order as a much more targeted effort than the president’s earlier one. Each of the countries will be under its own set of travel restrictions, though in most cases citizens of the countries will be unable to emigrate to the United States permanently and most will be barred from coming to work, study or vacation in America.
Iran, for example, will still be able to send its citizens on student exchanges, though such visitors will be subject to enhanced screening. Certain government officials of Venezuela and their families will be barred from visiting the United States. Somalis will no longer be allowed to emigrate to the United States, but may visit with extra screening.
Administration officials said that the new rules would not apply to legal permanent residents of the United States, and that visitors who currently hold valid visas from the countries listed will not have their visas revoked.
That means that students already studying in the United States can finish their studies and employees of businesses in the United States who are from the targeted countries may stay for as long as their existing visas remain valid. People whose visas expire will be subject to the travel ban, officials said.
People seeking access to the United States as refugees are not covered by the proclamation, officials said. Entry of refugees is currently limited by the president’s original travel ban, and officials said the administration was preparing new rules for refugees that should be announced within days.
Reaction to the president’s announcement was swift, as some critics of the original travel ban expressed similar concerns about the president’s latest effort to bar potential terrorists and criminals.
“Six of President Trump’s targeted countries are Muslim. The fact that Trump has added North Korea — with few visitors to the U.S. — and a few government officials from Venezuela doesn’t obfuscate the real fact that the administration’s order is still a Muslim ban,” said Anthony D. Romero, the executive director of the American Civil Liberties Union.
“President Trump’s original sin of targeting Muslims cannot be cured by throwing other countries onto his enemies list,” Mr. Romero said.
But administration officials — who have long rejected the characterization of the president’s travel restrictions as a “Muslim ban,” — noted that the latest effort also applies to non-Muslim countries and was based on a rigorous evaluation of each country’s security capabilities.
One official who briefed reporters on Sunday evening insisted that the president’s travel restrictions were “never, ever, ever” based on race, religion or creed.
In a statement released by the White House, Mr. Trump defended the new proclamation, saying that “we cannot afford to continue the failed policies of the past, which present an unacceptable danger to our country. My highest obligation is to ensure the safety and security of the American people, and in issuing this new travel order, I am fulfilling that sacred obligation.”
The president’s announcement comes after the administration conducted what they described as an in-depth, worldwide, 90-day review of the security measures in place in other countries to prevent terrorists or criminals from entering the United States by applying to emigrate or to visit with a tourist, work or education visa.
Mr. Trump called for the review — and a temporary ban on travel from several majority-Muslim countries — just days after being inaugurated. But a fierce legal challenge to the travel ban delayed the security assessment until the summer.
Officials said last week that most nations already met new, minimum standards for identifying and screening potential travelers and sharing investigative information with law enforcement agencies in the United States. Some nations that initially fell short of those standards agreed to implement changes to avoid travel restrictions.
But several countries either failed to meet those standards or flatly refused, officials said. Homeland Security officials recommended to Mr. Trump in a report last week that he impose the new travel restrictions on the residents of those countries. The president’s 15-page proclamation accepted the recommendations, spelling them out in detail.
The proclamation imposes the most severe restrictions on Syria and North Korea, which Mr. Trump says fail to cooperate with the United States in any respect. All citizens from those countries will be denied visas to enter the United States once the proclamation goes into effect.
Most citizens of Chad, Libya and Yemen will be blocked from emigrating to or visiting the United States because the countries do not have the technical capability to identify and screen their travelers, and in many cases have terrorist networks in their countries, officials said.
Officials said Somalia did, barely, meet the security standards set by the United States, but will still be subject to a ban on emigration and heightened scrutiny for travel because it is a safe haven for terrorists. Officials said that Iran was uncooperative and would be subject to a broad travel ban, but Mr. Trump made an exception for student and exchange visas.
In Venezuela, Mr. Trump restricted only the travel of government officials and their families, writing in the proclamation that the ban was focused on that group because they were “responsible for the identified inadequacies” in sharing information about travelers.
Mr. Trump’s original travel ban prevented all travel from citizens of seven countries: Iraq, Iran, Libya, Somalia, Sudan, Syria and Yemen. Iraq was later removed from a second version of the travel ban in March after American officials said it had improved its ability to screen passengers and share information with the United States. In the new security review, Sudan was deemed to meet the security standards and was removed from the list of countries with travel restrictions.
Homeland Security officials had described the previous ban as a temporary pause on travel from certain countries to allow for the review of security measures.
By contrast, the new travel restrictions will be in place indefinitely, officials said. The United States will consider lifting the restrictions on those countries affected only if they meet the new minimum standards, they said.
The president’s announcement could have a dramatic impact on the legal challenge to the previous travel ban, which is under consideration by the Supreme Court after the administration appealed lower court rulings that said the ban was unconstitutional and a breach of Mr. Trump’s authority.
Oral arguments in the case are scheduled for Oct. 10, but legal experts said that parts of the case could be moot because of the president’s decision to end that travel ban. Other parts of the case, including restrictions on refugees coming into the United States, were not affected by Sunday’s announcement.
A spokeswoman for the Justice Department said Sunday that the solicitor general would be submitting an update to the Supreme Court about the latest travel restrictions on Sunday evening. The spokeswoman said the administration would continue to defend the president’s “lawful authority to issue his executive order.”
But lawyers who filed challenges to the president’s previous travel ban left open the possibility that they would also challenge the new restrictions.
“This is an apparent effort to paper over the original sin of the Muslim ban, especially when just last week Trump said he wanted a ‘larger, tougher, more specific’ ban,” said Anthony D. Romero, the executive director of the American Civil Liberties Union.
The original travel ban was met with angry denunciations from civil rights activists and others who said the president was violating the Constitution by specifically targeting Muslims. They also criticized Mr. Trump’s administration for abruptly imposing the ban, causing confusion at airports as visitors were turned away by border agents who had not been briefed on the new policy.
Administration officials said on Friday that the new policy was the result of months of deliberation that included the State Department, the Department of Homeland Security, the White House and other agencies involved in security and the border.