Kerry, on a two-day visit to Beijing, had been expected to press China, North Korea's lone major backer, for more curbs on Pyongyang after it said it had successfully conducted a test of a miniaturized hydrogen nuclear device, though the United States has voiced scepticism as to whether it was that powerful.
China has insisted it is already making great efforts to achieve decentralization on the "Korean peninsula" and Wang rejected any "groundless speculation" on its North Korea stance, following remarks from U.S. officials that China could do more.
"We agreed that the UN Security Council needs to take further action and pass a new resolution," Wang told reporters at a joint briefing with Kerry.
"In the meantime, we must point out that the new resolution should not provoke new tensions."
Kerry said the two sides had agreed to an "accelerated effort" at the U.N. to reach a "strong resolution that introduces significant new measures" to curtail North Korea's ability to advance its nuclear and ballistic missile programs.
"It's not enough to agree on the goal. We believe we need to agree on the meaningful steps necessary to get the achievement of the goal," Kerry said.
The exchange of goods and services between China and North Korea was one area where steps could be taken to pressure Pyongyang back to talks, he said.
Kerry also said that shipping, aviation, trade of resources, including coal and fuel, and security at border customs, were key areas in the sanctions debate. North Korea is heavily reliant on China for oil, gasoline and trade.
"All nations, particularly those that seek a global leadership role, share a fundamental responsibility to meet this challenge with a united front," Kerry said.
He added that the US would take "all necessary steps" to honor security commitments to allies, signaling that the US was prepared to continue ramping up its military presence in the region, a move that would likely unsettle Beijing.
"North Korea poses an overt threat, a declared threat, to the world, and it has stated its intention to develop a thermonuclear weapon," he said. "In addition, it has made clear its intent to develop an intercontinental ballistic missile with the capacity to carry a nuclear warhead."
The 15-member UN Security Council said at the time of North Korea's test that it would begin working on significant new measures in response, a threat diplomats said could mean an expansion of sanctions.
Since then, diplomats said Washington and Beijing have been primarily negotiating on a draft resolution, but when asked on Saturday if they were nearing agreement, U.S. Ambassador to the United Nations Samantha Power said no.
After talks on Wednesday, which went hours past schedule, Kerry said details still had not been set.
In a sign that Beijing could be reluctant to take a more hardline stance on North Korea, state news agency Xinhua said it was "unrealistic to rely merely on China to press the DPRK to abandon its nuclear program, as long as the U.S. continues an antagonistic approach wrought from a Cold War mentality".
"Bear in mind that China-DPRK ties should not be understood as a top-down relationship where the latter follows every bit of advice offered by the former," Xinhua said, referring to North Korea by its official name, the Democratic People's Republic of Korea.
Xinhua commentaries are not official government pronouncements, but can be read as a reflection of official thinking. Wang added that sanctions should be seen as a path to negotiation, and not as a punitive end in themselves
South China Sea militarization
Kerry said that a need for the United States and China to find a way forward on easing tension in the South China Sea weighed heavily in talks.
"I stressed the importance of finding common ground among the claimants and avoiding a destabilizing cycle of mistrust or escalation," Kerry said. "Foreign Minister Wang Yi accepted the idea that it would be worth exploring whether or not there was a way to reduce the tensions and solve some of the challenges through diplomacy."
Wang said China's activities in the region, which have elicited unease from the U.S. and its allies, should not be construed as militarization.
"China has given a commitment of not engaging in so-called militarization, and we will honor that commitment," Wang said. "We cannot accept the allegation that China's words are not being matched by action."
His remarks came as Taiwan President Ma Ying-jeou said he planned a trip to the Taiwanese-held island of Itu Aba, known as Taiping Island in Taiwan, in the sea, a move a U.S. official called "extremely unhelpful" in resolving disputes over the waterway.
China claims almost all the disputed waters in the potentially oil- and gas-rich South China Sea, parts of which are also claimed by Brunei, Malaysia, the Philippines, Taiwan and Vietnam.
Kerry was in Cambodia on Tuesday after a visit to neighboring Laos as part of an effort to urge unity among leaders of the 10-nation Association of Southeast Asian Nations (ASEAN) on the sea issue before a summit with President Barack Obama next month.
China insists any disputes should be handled bilaterally.
