The Biden administration announced Thursday it will designate Ukraine for temporary protected status, allowing Ukrainians in the U.S. to remain in the country without fear of deportation for 18 months.

The announcement aims to protect Ukrainian nationals from deportation to a country in the throes of a Russian invasion, which has claimed hundreds of civilian lives and forced more than a million people to flee, according to latest estimates by the United Nations High Commissioner for Refugees, Filippo Grandi.

It would also allow eligible Ukrainians to apply for work permits.

“Russia’s premeditated and unprovoked attack on Ukraine has resulted in an ongoing war, senseless violence, and Ukrainians forced to seek refuge in other countries,” said Homeland Security Secretary Alejandro N. Mayorkas. “In these extraordinary times, we will continue to offer our support and protection to Ukrainian nationals in the United States.”

Roughly 28,000 Ukrainians in the U.S. are eligible to apply, according to estimates from the Center for Migration Studies in New York.

The new designation comes after dozens of lawmakers from both sides of the aisle wrote letters to the White House urging action.

“Ukraine clearly meets the standard for TPS as it is obviously too dangerous for Ukrainian nationals to return to Ukraine due to the ongoing armed conflict,” wrote a group of senators led by Sens. Richard J. Durbin, D-Ill., and Rob Portman, R-Ohio, on Monday.

The designation would primarily apply to students, business travelers and tourists who are in the U.S. on temporary visas but cannot safely return to their country, the lawmakers said.

“Granting TPS to the limited population of Ukrainians who are currently in the U.S. on a temporary basis will create a minimal disruption for our country, but forcing these individuals to return to a war zone would be unacceptable,” they wrote.

The Biden administration has faced growing calls in recent weeks to use temporary protected status more widely as an administrative pathway to immigration relief. Democratic lawmakers and advocates have pressed for the administration to designate or re-designate TPS to additional countries, including Central American nations, in an effort to grant some form of legal status to undocumented immigrants.

A dozen other countries are currently designated for TPS, including Haiti, Syria, Venezuela and Yemen.

Sen. Bob Menendez, D-N.J., chairman of the Senate Foreign Relations Committee and a signatory on Durbin and Portman’s letter, previewed the upcoming announcement earlier on Thursday. “I think that that’s going to happen,” Menendez said, based on his conversations with the Biden administration.

Suzanne Monyak contributed to this report.