WASHINGTON (AP) — The U.S. is sending a “few thousand” troops to the Middle East to bolster security and to defend Israel if necessary, the Pentagon said Monday. The announcement follows word that Israel has already launched limited raids across the border into Lebanon.

The additional forces would raise the total number of troops in the region to as many as 43,000.

The increased presence will involve multiple fighter jet and attack aircraft squadrons, Pentagon spokeswoman Sabrina Singh told reporters. U.S. officials said the total includes small numbers of other troops to augment the presence as well.

It follows recent strikes in Lebanon and the assassination of Hezbollah leader Hassan Nasrallah, a significant escalation in the war in the Middle East, this time between Israel and Hezbollah.

The additional personnel includes squadrons of F-15E, F-16, and F-22 fighter jets and A-10 attack aircraft, and the personnel needed to support them. The jets were supposed to rotate in and replace the squadrons already there. Instead, both the existing and new squadrons will remain in place to double the airpower on hand.

On Sunday, Defense Secretary Lloyd Austin announced that he was temporarily extending the USS Abraham Lincoln carrier strike group and its embarked air wing in the region. A U.S. official said the extension will be for about a month. A second carrier, the USS Harry S. Truman, departed Virginia last week and is enroute to Europe. It will head to the Mediterranean Sea and will again provide a two-carrier presence in the broader region. It’s not expected to arrive for at least another week.

At the White House, President Joe Biden said Monday that “I’m more aware than you might know” about reports that Israel is planning a limited ground incursion into Lebanon after nearly a year of fighting with Hezbollah, and said he wants a cease-fire immediately. Asked about the reports, Biden said, “I’m more aware than you might know, and I’m comfortable with them stopping. We should have a cease-fire now.”