President Trump signed an order Friday expanding his travel ban to six new countries, targeting nations the government says pose a threat because they don’t issue electronic passports or don’t do enough to share information with American authorities to vet their citizens looking to travel.

The six countries are Burma, Eritrea, Kyrgyzstan, Nigeria, Sudan and Tanzania. They join seven countries who are still part of the president’s previous travel ban: Iran, Libya, North Korea, Somalia, Syria, Venezuela and Yemen.

“It is fundamental to national security, and the height of common sense, that if a foreign nation wishes to receive the benefits of immigration and travel to the United States, it must satisfy basic security conditions outlined by America’s law-enforcement and intelligence professionals,” said White House press secretary Stephanie Grisham.

The new countries aren’t subject to a total ban.

Only immigrant applications from Burma, Eritrea, Kyrgyzstan and Nigeria will be blocked, while other travelers are not affected. For Sudan and Tanzania, only applicants under the diversity visa program will be blocked, a Homeland Security official said.

That means businesses can still bring in temporary workers and family members can still visit relatives here.

The official said the lower level of ban reflects the countries’ conditions.

“These six countries have a greater prospect of making improvements,” the official said.

The additional ban will take effect Feb. 22, so nobody traveling now will be affected, nor will those who already have visas. Anyone already in the U.S. is unaffected, too.

Based on past trends, Homeland Security said perhaps 12,000 people would be affected by the expanded ban.

Immigrant-rights groups complained that the expanded ban could harm vulnerable people.

“We are particularly concerned about Burmese refugees who may see America’s doors closed to them at a time of desperate need — including thousands of ethnic Chin, Karen, and Muslim Rohingya, who have fled severe persecution,” said Krish O’Mara Vignarajah, president of Lutheran Immigration and Refugee Service

Government officials said refugees are not affected.

Mr. Trump issued his first travel ban Jan. 27, 2017, on seven majority-Muslim countries, virtually banning all entry of citizens from those countries.

That derided as a “Muslim ban,” and was halted by federal judges.

Mr. Trump would make two subsequent revisions to narrow the ban and alter the countries covered, deleting some of the original nations and adding in two non-Muslim nations, North Korea and Venezuela.

The Supreme Court in 2018 ruled that version of the ban was legal on its face — though it left room for challenges on how the ban was carried out. Those challenges are still making their way through lower courts.

Homeland Security officials defended the new additions to the list, saying they were added after an extensive review of every country’s vulnerabilities and willingness to share information with the U.S. so that their citizens looking to travel to the U.S. can be properly vetted.

“DHS and the Department of State have informed each of the six countries about their specific deficiencies,” a Homeland Security official said, adding that countries can earn their way off the list by improving their cooperation.

That happened in April 2018 when Chad made enough improvements to be dropped from the travel ban, the official said.