U.S. Secretary of State John Kerry has arrived in Beijing for talks aimed at encouraging Chinese leaders to put more pressure on ally North Korea to end its nuclear weapons program.
Kerry arrived in the Chinese capital early Friday from South Korea, where he met Thursday with South Korea's president and foreign minister. The meeting followed the first-high-level talks earlier this week between North and South Korea in seven years.
With little progress in talks between Pyongyang and Seoul, South Korea says it will go ahead with the U.S. on planned joint military exercises that North Korea says will disrupt efforts at family reunions.
Speaking through a translator, South Korean Foreign Minister Yun Byung-sen said it is time to keep the pressure on Pyonyang.
"We share the view that a principled and effective two-track approach of pressure and dialogue is necessary," he said. "In this regard, based on firm ROK-U.S. collaboration, we will make greater efforts with China and other countries to achieve substantial denuclearization of North Korea."
China has a "unique and critical role" in bringing North Korea back to talks on its nuclear program, Kerry said.
"No country has a greater potential to influence North Korea's behavior than China, given their extensive trading relationship with the North."
China is helping, said Kerry, but there is more Beijing can do as the leading supplier of North Korean fuel and banking services.
"Our belief is that China can do more now to urge North Korea to begin taking action to come into compliance with its international obligations," he said. "And I will encourage China to use all of the means at its disposal to do so. Now I want to make it clear: China has responded."
North Korea has rebuilt some of its nuclear facilities in the absence of international talks, making President Kim Jong Un even more dangerous, said American Enterprise Institute analyst Michael Auslin.
"We understand less about what's going on in Kim Jong Un's North Korea than we did with Kim Jong Il's North Korea," Auslin said. "And that's something to be worried about. And from every indication we have, things are getting more uncertain and capricious there."
Which makes it even harder to know how best to approach President Kim, said Lou Goodman, a professor from American University.
"When will the regime be self-confident enough in its new consolidation to move ahead and develop some new initiatives?"
Kerry said China shares U.S. concerns about greater instability following the execution of the president's uncle, who was a leading Chinese ally. That is another change Washington and Beijing do not fully understand, said Auslin.
"We used to look at Jang Song Thaek and say 'okay, that's a lot of where the power lies.' We know there's connection with China. There is a stability there that we might not like, but there is a stability. Today I'm not sure you can say that."
In Thursday talks with President Park Geun-Hye, Kerry also sought to ease tensions between South Korea and Japan over a contested island with rich fishing rights that may contain large deposits of natural gas.