The Biden administration on Friday expanded an immigration relief program for Ukrainians in the U.S., saying Ukraine’s ongoing war with Russia justified offering temporary legal protections to tens of thousands of additional potential applicants.

The Department of Homeland Security said it would allow 166,700 more Ukrainians in the U.S. to apply for Temporary Protected Status, or TPS, an immigration relief program that allows migrants from crisis-stricken countries to obtain work permits and deportation protections.

The Biden administration first created a TPS program for Ukrainians in the spring of 2022, soon after Russian forces invaded Ukraine. The war is the largest conventional conflict in Europe since World War II, and the invasion triggered a mass exodus of millions of Ukrainian refugees, most of them women and children.