U.S. Vice President Mike Pence once again pledged that the Trump administration would move the U.S. embassy to Jerusalem, this time to Christian supporters of Israel who have become increasingly restive at President Donald Trump’s failure to make good on his campaign promise

“To the men and women of Christians United for Israel, this president hears you,” Pence said to cheers Monday evening at the annual CUFI conference in Washington. “This President stands with you. And I promise you that the day will come when President Donald Trump moves the American Embassy from Tel Aviv to Jerusalem. It is not a question of if, it is only when.”

Earlier Monday, a panel including Pastor John Hagee, who founded the movement 12 years ago, expressed concerns that Trump, who otherwise was presented at the conference as preferable to his predecessor, President Barack Obama, was losing credibility by not making good on his campaign promise. “Moving to Jerusalem would prove that our president stands by his word,” Hagee said.

Trump in June renewed a waiver on a law passed in 1995 mandating the move, as all of his predecessors have done, and has backed away from the pledge.

Pence, who has long been close to the pro-Israel community, has said several times that Trump would fullfill the promise.