WASHINGTON, July 19 (Xinhua) -- The U.S. military said on Friday that Pentagon has authorized the movement of military personnel and resources to Saudi Arabia to help deter "credible threats."

The move would provide "an additional deterrent, and ensures our ability to defend our forces and interests in the region from emergent, credible threats," U.S. Central Command (CENTCOM) said in a statement.

According to the statement,the Pentagon made the decision at the invitation of Saudi Arabia.

CENTCOM continually assesses force posture in the region, the statement added, without providing a specific number of personnel and types of resources that are being sent to Saudi Arabia.

Citing two defense officials, CNN reported late Wednesday that 500 U.S. troops are expected to be deployed to the Prince Sultan Air Base, located in a desert area east of the Saudi capital of Riyadh.

A small number of troops and support personnel are already on site with initial preparations being made for a Patriot missile defense battery as well as runway and airfield improvements, according to the officials.

Last month, the Trump administration announced a decision to deploy 1,000 additional troops to the Middle East. CNN noted that the troops to be sent to Saudi Arabia are part of that deployment plan.

The announcement of the U.S. force movement came at a moment when the regional situation is volatile.

U.S. President Donald Trump said on Thursday that a U.S. warship destroyed an Iranian drone in the Strait of Hormuz, but Tehran denied the U.S. assertion.

Iran's Islamic Revolution Guards Corps on Friday announced that it seized British oil tanker Stena Impero in the Strait of Hormuz because the vessel failed to respect international maritime rules while passing through the strait.

In a separate statement on Friday, CENTCOM said that it is launching Operation Sentinel, a multinational maritime effort to increase surveillance and security in key waterways in the Middle East.