United States senator met with North Koreans about student

While Trump has heaped praise on Xi for trying to contain North Korea, which counts on China for some 90 percent of its trade, the effort has delivered few results. "He's signaling to others that he understands this isn't working, and he's trying to defend himself, or justify himself, by saying that at least they tried as opposed to others who didn't even try".

But the U.S. officials said it will be at least a year before they can evaluate whether the North Koreans are feeling pressure because of China.

On Tuesday, a US official said USA spy satellites had detected movements recently at North Korea's nuclear test site near a tunnel entrance, but it was unclear if Pyongyang was preparing for a new nuclear test, perhaps to coincide with Wednesday's high-level talks.

Dozens of North Korean missile launches and two nuclear bomb tests since the beginning of a year ago have heightened tensions on the Korean peninsula.

Seoul was in close consultation with Washington over the matter, the official added. Pyongyang has vowed to develop a nuclear-tipped intercontinental ballistic missile capable of hitting the United States mainland. Chinese State Councilor Yang Jiechi and Gen. Fang Fenghui, the chief of the People's Liberation Army's Joint Staff, led their country's delegation.

Warmbier had planned to study in China in his third year of college and heard about Chinese travel companies offering trips to North Korea. At the bilateral talks tomorrow, officials say the USA is looking to use trade as a weapon with China to put more pressure on North Korea.

In the meantime, the USA will continue to fly, sail and operate wherever the freedom of navigation allows, according to Mattis.

His remarks came the day after after 22-year-old college student Otto Warmbier from Cincinnati, who had been imprisoned by the country since January 2016, died - only six days following his return to the United States.

Warmbier, an OH native and student at the University of Virginia, was arrested in North Korea in January 2016 while visiting as a tourist. "His family is incredible ... but he should have been brought home a long time ago", Trump said. In a statement about Warmbier's death released Monday, Secretary of State Rex Tillerson called on North Korea to free the three Americans who remain captive.

Top U.S. and Chinese diplomats and defense chiefs are meeting in the U.S. capital for security talks, and North Korea will get "top billing", according to Susan Thornton, the senior U.S. diplomat for East Asia. But it was unclear if Pyongyang was preparing for a sixth nuclear test. "But by no means will China, nor will Chinese society permit it to, act as a "U.S. ally" in pressuring North Korea", the Global Times said in an editorial.

Chinese officials were not immediately available for comment after the talks.

Without a clear alternative, the Trump administration remains committed to urging China to crack down on Pyongyang.

For his part, Tillerson doubled down on the current strategy, saying both the US and China agreed to stop doing business with United Nations -sanctioned North Koreans.

As U.S. tensions with North Korea intensify, the White House pushed China to put pressure on companies that do business in Pyongyang ahead of high-level security talks between Washington and Beijing Wednesday. At a briefing Tuesday, White House Press Secretary Sean Spicer said that a meeting between President Trump and North Korean leader Kim Jong-un is less likely to happen now.