LAS VEGAS — Defiant Republican governors on Wednesday demanded the Obama administration suspend plans to resettle thousands of Syrian refugees in their states, charging that screening challenges make it all but impossible to identify terrorists among those seeking refuge in the United States so soon after a series of attacks in Paris.

State leaders from New Mexico to Michigan pleaded with the president to suspend the refugee program — at least temporarily. Others, including Republican governors from Texas and Indiana, claimed the legal authority to block the federal resettlement efforts unilaterally.

“We have the independent authority to completely shut down these refugee relocation programs,” Texas Gov. Greg Abbott said in an interview with The Associated Press. “The states are saying we are not going to accept any more of these refugees until the United States comes up with an effective vetting program.”

Despite the tough talk, it may not be that easy.

The Refugee Act of 1980 dictates that refugee resettlement within the United States is managed by the federal government. State refugee coordinators are consulted by the federal government and the nine refugee resettlement agencies that have contracts with the government, but that consultation is largely to ensure the refugees are settled in cities with adequate jobs, housing and social services.

Individual states do not have the legal authority to block refugee placement.

That didn’t stop Indiana Gov. Mike Pence this week from issuing an executive order to block federal funding needed to administer the program.

“Posturing notwithstanding, this is a program that actually works on a collaborative basis between the federal government and states,” Pence said. “What we’ve essentially said is ‘we’re not collaborating with you.”’

Pence encouraged Obama to reconsider his plan to veto legislation introduced by House Republicans to require new screening requirements for Syrian and Iraqi refugees before they’re allowed into the United States.

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

The Islamic State group claimed responsibility for a series of attacks in Paris Friday that left 129 dead and hundreds wounded.

None of the suspects identified so far in the Paris attacks has been identified as a Syrian refugee and the German interior minister says the Syrian migrant passport found at the scene is likely a fake.