President Barack Obama announced Wednesday that he is nominating Commerce Secretary Gary Locke to be the U.S. ambassador to China.

During brief remarks at the White House, Obama said the United States could not have better representation in the “critical relationship” with China than Locke. Secretary of State Hillary Rodham Clinton stood alongside the president during the announcement.

The White House is keeping mum for now on who will replace Locke, but Rep. James Clyburn (D-S.C.) and U.S. Trade Representative Ron Kirk have been mentioned as possibilities.