The Obama administration is coming under increasing pressure from European allies to extend the deadline for an Iranian nuclear deal beyond June 30, a development that signals doubts about Tehran’s willingness to bargain and complicates the U.S. president’s relations with Congress on the talks.

Administration officials say the deadline — self-imposed by Washington and other powers negotiating with Iran — remains realistic despite signals from Britain and France that it likely will need to be extended amid news that Iran’s parliament wants to block inspections of the nation’s military sites.

State Department spokesman John Kirby said Monday that the “date is not more important than the deal” but stressed that administration officials “continue to be focused on June 30th as the goal and the objective.”