'Dozens' of Marines augmenting US embassy security in Turkey, Israel, Jordan

The move comes amid protests against the U.S. Embassy opening Jerusalem Monday.

The news comes on the same day that the U.S. opened its embassy in Jerusalem and at least 55 people were killed during protests in Gaza, according to Gaza's health ministry.

Demonstrations against the U.S. Jerusalem embassy opening also took place on Monday in both Turkey and Jordan.

"Augmentation is conducted regularly when a diplomatic post faces a heightened threat environment. Due to operational security reasons, we cannot discuss these units' size, capabilities, and deployment timelines," said Lt. Cmdr. Rebecca Rebarich, Pentagon spokeswoman.

NBC News was first to report that "dozens" of Marines would be supplementing security in Turkey, Israel, and Jordan.

The U.S. Embassy in Ankara last issued a statement on May 11, warning that the relocation of the U.S. embassy from Tel Aviv to Jerusalem could spark protests. But there have not been similar alerts issued by embassies in Israel and Jordan.

The last alert issued by the U.S. Embassy in Jordan was in late February – related to demonstrations in the West Bank.

Recent alerts from the U.S. embassy in Tel Aviv prohibited U.S. government employee travel to the Golan Heights due to regional tension.

ABC News' Luis Martinez contributed to this report.