President Trump is expected to announce today that the U.S. will recognize Jerusalem as the capital of Israel and initiate a process of moving the U.S. Embassy from Tel Aviv to Jerusalem.

The move would upend decades of international peace efforts. The announcement has already sparked a massive international backlash, with leaders of Britain, France, Iran, Jordan, Egypt, Turkey, the Arab League and other nations all criticizing the move. Palestinian President Mahmoud Abbas warned of “the dangerous consequences such a decision would have to the peace process and to the peace, security and stability of the region and of the world.” Palestinians have called for “three days of rage”— protests across the Israeli-occupied territories.

Control of Jerusalem is one of the most contested issues between Israelis and Palestinians. The Israeli military seized control of East Jerusalem in 1967 and has occupied the territory ever since. Palestinians, however, have long seen Jerusalem as the capital of their future country. Since 1967, the U.N. Security Council and U.N. General Assembly have passed dozens of resolutions calling for Israel to end its occupation of East Jerusalem.

Currently 86 nations have their embassies in Tel Aviv. No country has an embassy in Jerusalem. This is Pope Francis, speaking Tuesday.

Pope Francis: “My thoughts go out to Jerusalem. In this respect, I cannot hide my deep concern about the situation that has developed in the last days. And in the meantime, I make an urgent appeal to everybody to respect the status quo of the city, in accordance with the relevant resolutions of the United Nations. I pray that wisdom and prudence can prevail to avoid adding new elements of tension in a world scenario already convulsive and scarred by so many cruel conflicts.”