Adm. Samuel Locklear III, commander of U.S. Pacific Command, responds to questions from Sen. John McCain (R-Ariz.) about North Korea at a Senate Armed Services Committee hearing on U.S. Pacific Command and U.S. Forces in Korea in review of the Defense Authorization Request for fiscal year 2014 and the Future Years Defense Program. (Sandi Moynihan/The Washington Post)

The United States is capable of responding to an attack from North Korea, but Washington and its allies must work hard to “preserve the peace,” the American commander overseeing operations on the Korean Peninsula said Tuesday as U.S. senators urged him to engage China more forcefully in that effort.

Testifying before the Senate Armed Services Committee, Navy Adm. Samuel J. Locklear faced pointed questions about China’s patronage of Pyongyang, a line of inquiry that made it clear that several lawmakers think Beijing has not used its leverage over North Korea to end a series of threats and provocative actions.

“I would think that China could play a key role in influencing the bellicose rhetoric and restoring some sense of calm to the peninsula,” Locklear said. “I believe sometimes the Chinese, in the way they approach it, are more nuanced than we are.”

Locklear said he hasn’t consulted with his Chinese counterparts in the past two weeks, as an escalating stream of threats from North Korea put the peninsula on a war footing. He said military-to-military contacts between the two countries happen at a higher level.

“It seems to me that we need to be clearer with China as to what our expectations are, because this is a danger to them,” Sen. Kelly Ayotte (R-N.H.) said at the hearing. “I think that is particularly important, given that North Korea relies on China essentially for its economic existence.”

At the White House, spokesman Jay Carney welcomed Chinese President Xi Jinping’s oblique warning last weekend that “no one should be allowed to throw the region, even the whole world, into chaos for selfish gains,” a statement the administration has said was directed at Pyongyang.

“We have absolutely been consulting with the Chinese about the need to use their influence on the North Koreans,” Carney said. “We’ve also been in discussions with Moscow about this.”

He said those conversations will continue when Secretary of State John F. Kerry visits Beijing this week.

China experts expressed skepticism about what Washington can reasonably expect from Beijing, noting that many administrations have been unable to coax North Korea’s most important ally to exert greater pressure on Pyongyang.

“Successive administrations come into office and convince themselves they can solve the North Korea problem,” said Andrew Scobell of the Rand Corp. “Successive administrations have been sorely disappointed with what China is able to deliver.”

Locklear said the United States and South Korea have consulted closely on how they would react to an attack by Pyongyang on the south, but he offered no details on the response or the lengths to which Washington has agreed to go to defend Seoul.

The United States and South Korea recently signed a revised security pact that outlines the type of cooperation Seoul could expect in the event of an armed conflict. But the details of the U.S. commitment to defend South Korea are classified, Pentagon officials said.

“It’s hard for me to speculate exactly how those scenarios would play out,” Locklear said. “We have the ability to quickly consult with each other and to bring the forces that would be necessary.”

The commander said the U.S. military is capable of shooting down North Korean missiles fired toward the United States or its allies in the region. But he said he would not support shooting down a missile if its course suggested that it would land in the ocean.

North Korea on Tuesday continued to warn that war is imminent, urging all foreigners and foreign-run businesses in the South to make evacuation plans.

The North “does not want to see foreigners in South Korea fall victim to the war,” the country’s state-run news agency said in a statement attributed to the Korea Asia-Pacific Peace Committee, an arm of the ruling Workers’ Party.

Chico Harlan in Seoul contributed to this report.