NEW YORK — Deputy U.S. Trade Representative (USTR) Demetrios Marantis assumed the top post at the federal agency March 15.

Marantis temporarily takes over for USTR Ron Kirk, who is departing after four years in President Obama’s Cabinet, the agency said.

Marantis will remain as acting USTR until a replacement is nominated and confirmed. He was confirmed for his previous role by the U.S. Senate in May 2009 and has been responsible for trade negotiations and enforcement in Asia and Africa, including negotiations in the Trans-Pacific Partnership, the U.S.-China Joint Commission on Commerce and Trade, and the Asia Pacific Economic Cooperation Forum, among others.

He also played a role in the negotiation and congressional passage of the U.S.-South Korea free-trade agreement, which became effective March 15, 2012.