The U.S. is sending additional warships and thousands of Marines to the Middle East to increase security in the wake of Iranian attempts to seize commercial ships there.

Defense Secretary Lloyd Austin on Thursday approved the deployment of the USS Bataan amphibious readiness group and the 26th Marine Expeditional Unit to the Gulf region, according to U.S. officials. The readiness group consists of three ships, including the Bataan, an amphibious assault ship. An expeditional unit usually consists of about 2,500 Marines.

In an announcement, U.S. Central Command said the deployment will provide "even greater flexibility and maritime capability in the region.” The announcement did not name the ships, but U.S. officials detailed the units involved in the deployment on condition of anonymity to discuss troop movements.