Obama, Xi talk nuclear security

US President Barack Obama and his Chinese counterpart Xi Jinping agreed on Thursday to enhance global nuclear security cooperation and to work to narrow differences over maritime conflicts in the South China Sea, officials said.

"The presidents of the two countries had candid and in-depth exchange of views on a variety of issues ... and reached an important consensus. The meeting was positive, constructive and fruitful," Zheng Zeguang, China's assistant foreign minister, told reporters.

Obama met with Xi on the sidelines of a global nuclear security summit near the White House that opened Thursday. He also called jointly with the leaders of Japan and South Korea for further steps to deter North Korea after the country's recent nuclear provocations.

"President Xi and I are both committed to the denuclearization of the Korean Peninsula," Obama said before sitting down to meet with Xi. "We're going to discuss how we can discourage actions like nuclear missile tests that escalate tensions and violate international obligations."

The United States has long pressured China, an ally of North Korea, to use its influence to press North Korea to give up its nuclear weapons program.

Obama planned to raise other issues during his meeting with Xi as well, including the disputed South China Sea where China is asserting territorial claims despite competing claims by neighboring countries. Xi has said Beijing won't accept international acts that violate its sovereignty.

"I very much appreciate President Xi's willingness to have conversations on these issues in a constructive way, Obama said.

Xi told reporters through a translator that the US and China would deepen ties on trade, law enforcement and climate change. He said the two economic powers must work together to promote peace and confront the rising global terror threat.

"China and the US have a responsibility to work together," Xi said. As for their "disputes and disagreements," the Chinese leader said the two sides could "seek active solutions through dialogue and consultation."

At the conclusion of the meeting, the US and China released a joint statement calling for robust collaboration to improve nuclear security "for the common benefit and security of all."

North Korea, extremist groups in spotlight

During the broader summit, Obama held a rare joint meeting with Japanese Prime Minister Shinzo Abe and South Korean President Park Geun-hye. All three leaders urged the world community to stand firmly behind recently-imposed sanctions on Pyongyang.

Park warned North Korea that the global community "will by no means" condone its provocations. North Korea has recently warned it could strike South Korea's presidential palace or even the US mainland, while its propaganda outlet posted a video depicting a nuclear attack on Washington.

While leaders spent most of Thursday focused on North Korea, the primary theme of this year's summit concerns the so-called "Islamic State" (IS) group and other terrorist organizations who could someday gain access to nuclear materials.

To this end, the US said a strengthened nuclear security agreement will take effect shortly following ratification by a critical mass of countries. The stricter rules include new criminal penalties for smuggling nuclear material and enhanced security standards for fissile material and nuclear facilities worldwide.

bw/jr (AP, Reuters, dpa)