WASHINGTON (AP) — The Trump administration notified Congress on Friday that it plans to send about 1,500 additional troops to the Middle East amid heightened tensions with Iran, officials said.

Members of Congress were notified a day after a White House meeting to discuss Pentagon proposals to bolster the U.S. force presence in the Middle East.

The officials spoke on condition of anonymity because the troop plans have not yet been formally announced.

The forces would number "roughly" 1,500 and would deploy in the coming weeks "with their primary responsibilities and activities being defensive in nature," according to a copy of the notification obtained by The Associated Press.

Their mission would include protecting U.S. forces already in the region and ensuring freedom of navigation, the notification said.

Earlier this week, officials said Pentagon planners had outlined plans that could have sent up to 10,000 military reinforcements to the region. Acting Defense Secretary Patrick Shanahan later said planners hadn't settled on a figure.

The U.S. began reinforcing its presence in the Persian Gulf region this month in response to what it said was a threat from Iran.

In early May, the U.S. accelerated the deployment of an aircraft carrier strike group to the Mideast and sent four B-52 bomber aircraft to the region. The Pentagon also decided to move a Patriot air-defense missile battery to an undisclosed country in the area.