Amid a growing political controversy, the Obama administration on Wednesday reminded state officials across the country that states do not have legal authority to refuse to accept Syrian refugees.

The Office of Refugee Resettlement said in a letter to state resettlement officials that states may not deny benefits and services to refugees based on a refugee’s country of origin or religious affiliation.

States that do not comply with the requirement would be breaking the law and could be subject to enforcement action, including suspension or termination of the federally funded program, according to the letter, signed by the director of the federal resettlement office, Robert Carey.

The letter came after more than two dozen governors, mostly Republicans, vowed to block efforts to resettle Syrian refugees in their states following the Nov. 13 terrorist attacks in Paris. The governors said they fear that militants planning a terror attack could enter the country under the guise of seeking refuge from war-torn Syria. In the House, lawmakers have voted overwhelmingly to erect higher hurdles for Syrian and Iraqi refugees.

The Obama administration counters that the vetting process is thorough and can take up to two years. President Barack Obama has said the U.S. will remain a welcoming place for refugees from around the world.

The letter from the federal resettlement office said would-be refugees “are subject to the highest level of security checks of any category of traveler to the United States.” The screening process is “multi-layered and intensive” and involves multiple law enforcement, national security and intelligence agencies across the federal government, the letter said.

A spokesman for the Texas Health and Human Services Commission, which oversees refugee resettlement in the state, said the letter will not change the state’s position of blocking Syrian refugees.

The commission will continue to follow the directive of Republican Gov. Greg Abbott, who has called for Texas not to participate in the resettlement of Syrian refugees, said Bryan Black, a spokesman for the Texas commission. A spokesman for Abbott declined to comment.

The letter sent Wednesday, first reported by the Houston Chronicle, largely tracks with what legal experts have been saying since Abbott and other governors said they would not accept Syrian refugees due to security concerns fueled by terrorist attacks in Paris. Abbott has cited a specific part of the law that he says gives him authority to block Syrians, but experts largely have disagreed.

Roughly 2,200 Syrian refugees have been allowed in over the last four years. Obama has outlined a goal of bringing 10,000 more Syrian refugees to the U.S. during the current budget year.

The House bill would add a requirement for the Homeland Security secretary, along with the head of the FBI and the director of national intelligence, to certify that each refugee being admitted poses no security threat.

A spokeswoman in the Department of Health and Human Services, which oversees the resettlement office, said 49 states and the District of Columbia have refugee resettlement programs. Wyoming does not have a refugee resettlement program.

(AP)