Pence was among more than 25 U.S. governors, mostly Republicans, who called on President Barack Obama to stop resettling refugees fleeing Syria's civil war after November attacks by militants in Paris that killed 130.

Governors have cited concerns that some refugees could be associated with Islamic State, which claimed responsibility for the attacks.

The suit brought by the American Civil Liberties Union on behalf of Exodus Refugee Immigration Inc was among the first challenging governors' moves to block resettlement.

"The State’s conduct clearly discriminates against Syrian refugees based on their national origin," U.S. District Judge Tanya Walton Pratt said in a ruling granting the preliminary injunction.