US Secretary of State John Kerry and Chinese Foreign Minister Wang Yi met for more than four hours and said their discussions were "constructive" and "candid." But at a joint news conference, they presented sharply opposing positions on the two issues.
Kerry acknowledged that "our differences will continue to test us." Still, he stressed that the world benefits when the United States and China are able to work together, including on the Iran nuclear deal and climate change.
On North Korea, Kerry said the United States wanted new UN Security Council action that would impose "significant new measures" to punish Pyongyang for its test this month and boost pressure on the North to return to disarmament talks.
"There's been a lot of talk about North Korea through these past years. Now we believe is the time for action that can bring North Korea back to the table," Kerry said.
Wang said China, which is North Korea's most important ally, chief trading partner and a key source of economic assistance, agreed on the need for a new resolution. But he suggested that Beijing would not support new penalties even though it has condemned the testing. "Sanctions are not an end in themselves," he said.
"The new resolution should not provoke new tension in the situation, still less destabilize the Korean Peninsula," Wang said.
Kerry noted that sanctions had brought Iran to the nuclear negotiating table. "More significant and impactful sanctions were put in place against Iran, which did not have a nuclear weapon than against North Korea, which does."
"All nations, particularly those who seek a global leadership role, or have a global leadership role, have a responsibility to deal with this threat," he said, referring to China.
Kerry said the sides agreed both on the need for a strong new resolution on North Korea, but also to accelerate talks on what that would entail.
"It's good to agree on the goal. But it's not enough to agree on the goal, we believe we need to agree on the meaningful steps necessary to get to the achievement of the goal to the negotiations that result in denuclearization," Kerry said.
Wang also took umbrage at US complaints that China is not doing as much as it can with the leverage it has on North Korea. He noted that China's position has been consistent in opposing North Korea's nuclear weapons program and supporting a diplomatic resolution to the matter.
"For many years China has been working hard to implement these," he said. "We have delivered on our obligation."
Kerry said China is North Korea's main link to the outside world, and that it could do more to limit cross-border transactions that benefit North Korean leader Kim Jong Un and his government.
Kerry also called on China to halt land reclamation and construction of airstrips in disputed areas of the South China Sea. Those steps have alarmed its smaller neighbors.
"I stressed the importance of finding common ground among the claimants and avoiding the destabilizing cycle of mistrust or escalation," Kerry said.
Wang denied that China has was doing anything other than protecting its territorial sovereignty. He rejected assertions by the United States and others that China was not interested in peaceful resolutions to the disputes or militarizing the areas.
In a later meeting with Chinese President Xi Jinping, Kerry hailed the "critical role" China played in the Iran nuclear agreement and on tackling global warming.
"The effort on climate was really historic and you made a key decision with President Obama to change the whole debate," Kerry said.
Xi, who met with Kerry at the Great Hall of the People in the heart of Beijing, described the bilateral relationship as "smooth and on the way up in the past year."
"Generally speaking, when China and the United States work together we can make good things happen with win-win results for both sides and that contributes to peace, prosperity and stability in the world," Xi said.
China claims sovereignty of much of the territory in the South China Sea. It rejects claims from countries such as the Philippines and Vietnam and has bristled at U.S. warnings that its activities threaten the freedom of navigation in some of the world's busiest commercial shipping lanes.
Taiwan, Malaysia and Brunei also have overlapping claims in the strategically vital sea, through which around $5 trillion in world trade passes each year.
The US says it takes no position on the claims but says developments in the South China Sea are a national security interest. It has urged that the disputes be settled peacefully and that a binding code of conduct be established for the area.
Tensions have been especially high since Beijing transformed seven disputed reefs into islands, where it is now constructing runways and facilities that rival claimants say can be used militarily. China has said it built the islands primarily to foster safe civilian sea travel and fishing.
In response, the US sent a guided-missile destroyer close to one of the Chinese-built islands, called Subi Reef, in October in a challenge to Beijing's territorial claims, sparking warnings from China. US officials vowed to continue maneuvers to protect freedom of navigation and overflight.
Recent developments, including China's movement of an oil rig into a zone disputed with Vietnam and warnings against Philippines overflight of what it claims to be its territory, have raised those levels of concern.
China dismisses the warnings as unwarranted, but has harshly criticized a US-Philippines defense pact that allows American forces, warships and planes to be based temporarily in local military camps. China says that will "escalate tensions and undermine peace and stability in the region," echoing language the United States uses to criticize China's actions.
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