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.