It is unclear whether Israel will be involved in constructing the pier.

President Biden will announce in his State of the Union on Thursday that he is ordering the U.S. military to build a floating pier off Gaza, in what the White House called an “emergency mission” that would allow hundreds of truckloads of additional aid to be delivered by sea to Gazans who are on the brink of starvation.

The project will take several weeks, involving hundreds or thousands of U.S. troops on ships just off shore, in keeping with Mr. Biden’s mandate that no American soldiers be on the ground inside Gaza as the conflict rages. Briefing reporters, administration officials said that the port would be constructed in cooperation with other countries in the region, but it was unclear whether Israel would be joining the effort.

The new facility, if opened as scheduled, could provide another way to get truckloads of aid into the region. But it would not solve the central problem that the trucks have been unable to deliver their goods while Israeli bombing remains fierce in the South. Nor would it address the chaos that accompanied the deliveries.

A convoy of aid trucks last week was overrun by Gazans desperate for food and water, leading to more than 100 deaths when Israeli soldiers opened fire and many people were trampled in the chaos.

The announcement came just hours before Mr. Biden was scheduled to deliver the State of the Union address, which family members of some of the hostages being held by Hamas since the Oct. 7 terrorist attack in Israel are expected to attend. The new project gives Mr. Biden a concrete project to point to at a time that he is under sharp criticism for not reining in Israel’s attacks, and moving too slowly to address the humanitarian catastrophe unfolding in Gaza.

It is unclear where the new floating port or pier will be built, though the Army Corps of Engineers has long experience in the rapid construction of floating facilities to accommodate U.S. military operations. Based on the description provided by White House and military officials, this one would be built from U.S. ships, and then moved close to shore, attached to some kind of temporary causeway.

The new seaport, when completed, would be an additional route for humanitarian aid, which is currently limited to two land crossings into the southern part of Gaza. Officials said Thursday that a third land crossing, into the northern part of Gaza, could open to limited deliveries within a week.

Mr. Biden also recently ordered the U.S. military to drop aid into Gaza by air. American pilots dropped their fourth load into the territory on Thursday.