Defying dire, worldwide warnings, President Donald Trump on Wednesday declared Jerusalem as Israel's capital, a move upending decades of U.S. policy and carrying unclear consequences for Mideast peace efforts.

During the announcement Trump declared that previous presidents have made the promise to do this and failed, but "today I am delivering."

He described the move as the "recognition of reality" and "the right thing to do."

The president also called on the U.S. State Department to begin the process of moving the U.S. Embassy in Israel to Jerusalem from Tel Aviv, his decision to recognize Jerusalem as Israel's capital risks infuriating the Muslim world, and potentially sparking protests that could fray American alliances in the world's most volatile region.

Trump administration officials cast the president's announcement as a simple acknowledgement of the "historical and current reality" of Jerusalem, which Israel effectively controls but whose status has been contested for centuries. But any presidential pronouncement, even couched as Trump's personal opinion, breaks from Washington's painstakingly maintained position of neutrality, which has held that the city's ultimate fate must be determined through Israeli-Palestinian negotiation.

Ahead of Trump's White House speech, Arab and Muslim leaders spoke about the potential for violence. In Gaza, hundreds of Palestinian protesters burned American and Israeli flags. They also waved Palestinian flags and banners proclaiming Jerusalem as their "eternal capital," language that Israelis similarly use.

Even America's closest allies in Europe questioned the wisdom of Trump's radical departure from past U.S. positions. Trump faced a deadline this week on whether to move the U.S. Embassy to Jerusalem, not on stating his view or his nation's on whether Jerusalem should be considered the Israeli capital.