President Barack Obama's nominee for U.S. ambassador to China says the Chinese can and must do more to pressure North Korea to give up its nuclear weapons program.

Commerce Secretary Gary Locke, a former governor of Washington state, would be the first Chinese-American to serve as ambassador to China if confirmed.

He told a Senate committee Thursday that China has realized it must step up to defuse the tensions between North and South Korea after recent provocations by the North. China is reclusive North Korea's only major ally.

Locke would replace Jon Huntsman, who resigned in April to explore a presidential bid. Senate Foreign Relations Committee Chairman John Kerry says Locke is a "good and wise" choice for the job.