The United States will "put pressure" on China to take action against North Korea's nuclear weapons program, the US ambassador to the United Nations said Sunday, days before a high profile visit by China's president.
"The only country that can stop North Korea is China and they know that," Ambassador Nikki Haley told ABC's This Week in an interview broadcast on Sunday. "We're going to continue to put pressure on China to have action."
Chinese President Xi Jinping is scheduled to meet Donald Trump on April 6 and 7 at the US president's Mar-a-Lago resort in Florida for their first face-to-face encounter.
It is being held amid rocky US-China relations over North Korea's nuclear and missile programs, trade and other issues.
On Thursday, Trump predicted a "very difficult" summit, noting the disputes over trade policy between the world's two most powerful nations and leading economies.
But Haley emphasized that at the Florida meeting "the most important conversation will be how we're going to be dealing with the nonproliferation of North Korea."
Beijing, increasingly frustrated with Pyongyang's nuclear and missile activities, has announced a suspension of all coal imports from the North until the end of the year.
Haley deemed that measure -- which was in keeping with UN sanctions against North Korea over its nuclear program and missile program -- insufficient, saying that coal is "going in other ways."
"At some point, we need to see definitive actions by China condemning North Korea and not just calling them out for it," she said.
Since taking office Trump has left open the possibility of military action against North Korea.
Following that country's early March missile tests, which came provocatively close to Japan, the US leader emphasized his administration's commitment to "deter and defend against North Korea's ballistic missiles using the full range of United States military capabilities."
Former US defense secretary Ash Carter, who served under Barack Obama, said the US has "always had all options on the table."
Also speaking on ABC, he recalled that the United States drew up a "preemptive strike plan" in 1994 to knock out North Korea's Yongbyon reactor, during a confrontation over its nuclear program.
"We have those options," he said. "We shouldn't take them off the table."
But he said a US strike on North Korea would likely trigger a North Korean attempt to invade South Korea.
"This is a war that would have an intensity of violence associated with it that we haven't seen since the last Korean War," he said.
"Seoul is right there on the borders of the DMZ, so even though the outcome is certain, it is a very destructive war. And so one needs to proceed very carefully here."
He said Washington should continue to pressure China to lean on North Korea, but was not optimistic that would lead to anything.
Beijing fears a potential North Korean collapse, which would result in "a unified Korea allied with the United States on their border," Carter said.