U.S.: China sends 'positive signals' it will help defuse North Korea crisis

China sent the Trump administration "positive signals"  that it will increase economic sanctions to pressure ally North Korea to abandon its development of nuclear weapons and missiles, a threat that has raised the prospect of a military confrontation with the United States, the State Department revealed Monday.

“We’ve gotten a lot of positive signals from the Chinese but it takes time,” Susan Thornton, acting assistant secretary for East Asian and Pacific affairs, said on a conference call with reporters. “You don’t know if these kinds of economic pressure will work until it works.”

U.S. diplomats will meet with the Chinese and American allies at the United Nations later this month to discuss the way forward, Thornton said. But if the Chinese are unsuccessful, the U.S. will move to increase pressure on North Korea on its own.

“We’re going to be watching what the Chinese do,” she said. “We’re going to work with China and see if we can get them to do more. And if they decide they’re not going to work with us or not cooperate with us, then we’re going to have to change tack and try something else, maybe on our own.”

Meanwhile, North Korea’s deputy U.N. ambassador accused the U.S. of turning the Korean peninsula into “the world’s biggest hotspot” and creating “a dangerous situation in which a thermonuclear war may break out at any moment.”

Kim In Ryong told a news conference Monday that U.S.-South Korean military exercises being staged now are the largest-ever “aggressive war drill.” He said North Korea’s measures to bolster its nuclear forces are self-defensive “to cope with the U.S. vicious nuclear threat and blackmail,” and he said his country “is ready to react to any mode of war desired by the U.S.”

China is considered key to changing North Korea's behavior because it is an economic lifeline for its much smaller neighbor. But China has been reluctant in the past to use its leverage because its fellow communist country serves as a buffer between Chinese territory and U.S. troops stationed in South Korea. The Beijing government also worries about a flood of refugees crossing into China if it allowed the isolated nation's economy to collapse.

Thornton said the U.S. is not interested in "conflict or regime change" in North Korea, which is ruled by totalitarian leader Kim Jong Un, but that it is looking for some kind of signal from the mercurial Kim that his government is willing to stick to its international commitments to abandon its current path of developing and testing nuclear weapons and ballistic missiles that could reach the United States.

A missile test on Sunday resulted in an explosion almost immediately after liftoff. The test came as a U.S. aircraft carrier sailed in waters off the Korean peninsula, and hours before the Vice President Pence arrived in South Korea.

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Pence warned North Korea on Monday that the "era of strategic patience is over" and that all options are on the table if Kim continues to threaten the region with his missile and nuclear testing programs. Speaking at the Demilitarized Zone that separates North and South Korea, Pence cited U.S. military strikes in Syria and Afghanistan this month as proof of President Trump’s willingness to use force, if necessary.

"North Korea will do well not to test his resolve or the strength of the armed forces of the United States in this region," Pence said.

North Korea has conducted five nuclear tests since 2006, the last in September. It also has conducted numerous medium- and long-range missile tests since Kim took power in 2011.

“We really need to have some kind of demonstrable change in North Korean behavior,” Thornton said. “Such signals would not include things like launching illegal missiles, as happened over the weekend,” she added.

Contributing: The Associated Press