WASHINGTON (JTA) — President Barack Obama said he conveyed to his successor Donald Trump that moving the U.S. Embassy to Jerusalem could be “explosive.”

“Obviously it’s a volatile environment when sudden unilateral moves are made that speak to the core issues or sensitivities of either side. That can be explosive,” Obama said Wednesday at his final news conference when asked whether he had consulted with Trump about moving the embassy from Tel Aviv.

He said his administration’s message to the Trump transition team was “pay attention to this, this is volatile stuff, people feel deeply and passionately about this.”

Obama said he understands that it is important to give a new president a wide berth on policy issues.

“I think it is right and appropriate for a new president to test old assumptions and re-examine the old ways of doing things, but if you’re going to make big shifts in policy … you want to be intentional about it, you don’t want to be off the cuff when it comes to an issue this volatile,” the outgoing U.S. leader said.

Trump’s pick for ambassador to Israel, his longtime lawyer David Friedman, has said he favors moving the embassy. Trump campaigned saying he would move the embassy, but his transition team has declined to offer a timeline for the action.

Congress recognized Jerusalem as Israel’s capital in 1995, but successive presidents have exercised a waiver that allows them to delay the move for national security reasons.

At the news conference, Obama again defended his decision last month to allow through the United Nations Security Council a resolution condemning Israeli settlement expansion. It was the first time Obama had allowed through a resolution that Israel opposed.

He noted his own multiple attempts to restart peace talks between Israelis and Palestinians had ended in failure, and said that settlement expansion was eroding the prospect of a two-state solution.

“It was important for us to send a signal that this moment may be passing,” the president said. “Hopefully that creates a debate inside Israeli and Palestinian communities that won’t immediately result in peace but will at least lead to a more sober assessment.”