American embassies around the world have been warned by the State Department to increase security in the event that President Trump delivers an announcement saying the U.S. acknowledges Jerusalem is Israel’s capital later this week.

State Department officials have said the warning was issued in the past week, Politico reported Monday.

The status of Jerusalem is highly controversial, with both Israelis and Palestinians claiming it as their capital. The warning comes amid concern that recognizing Jerusalem as the capital of Israel would anger the Arab world.

Some Arab leaders have requested Trump not alter the U.S.’s position regarding Jerusalem because it would rule out the possibility of a peace agreement between Israel and Palestine. Additionally, they have said it might encourage protests and terrorism.

For example, Hamas, a Palestinian militant Islamic group, has said they would call for a new Palestinian uprising if the U.S. named the city the capital of Israel.

“The impending Jerusalem announcement has me very worried about the possibility of violent responses that could affect embassies,” one State Department official said, according to Politico. “I hope I’m wrong.

The U.S., along with many other nations, has not identified Jerusalem as Israel’s capital and have maintained the decision must be a result of peace talks between Israelis and Palestinians.

Trump will make an appearance at the National Defense University on Wednesday, where he is anticipated to elaborate on his position concerning Jerusalem.