WASHINGTON — Secretary of State John Kerry urged Congress on Wednesday to adopt a landmark 12-nation Asia-Pacific trade deal, arguing that rejection would badly damage U.S. credibility and national security.

Kerry said failure to pass the Trans Pacific Partnership would not only hurt American business but embolden rivals and enemies like China and North Korea as well as cast doubt among U.S. allies in the region over American resolve.

He said rejection would amount to “a unilateral ceding of American influence and power and will have grave consequences,” notably in the Asia Pacific.

“Either the United States of America is an Asia-Pacific power or we are not and the ‘not’ carries with it serious consequences,” Kerry said. He said China and North Korea would see rejection of the deal as a sign of U.S. weakness. Beijing would see it as an invitation to continue aggressive activities in the South China Sea, and Pyongyang would be less likely to halt provocative nuclear and missile rests.

“The TPP will reinforce our status as a world leader,” Kerry said. “We can’t sit on the sidelines and expect to send a credible message to partners or potential partners. They would be affected by us turning our back on an agreement.”

The agreement would lower or eliminate thousands of tariffs and enshrine quality and worker rights standards among its signatories. However, both presidential candidates are opposed to the TPP, although Democrat Hillary Clinton helped negotiate it while she was secretary of state, and prospects for congressional passage appear dim.