China's Xi meets with Obama during security summit

Talks on Thursday between US President Barack Obama and China's President Xi Jinping were constructive, as both sides tried to come to an agreement over the South China Sea issue.

However, they did not manage to solve it, said China's Xinhua news agency.

Xi Jinping and Barack Obama agreed to increase cooperation on nuclear security worldwide and to do more on cyber security in the nuclear security summit meeting in Washington. Both also agreed to continue to work on a bilateral investment treaty, said Zheng Zeguang, China's assistant foreign minister.

According to Zeng's statements, China and US are still divided over the South China Sea despite US missile defence plans following North Korea's recent nuclear and rocket tests.

Obama's deputy national security adviser, Ben Rhodes, said on Tuesday that China had stepped up pressure on North Korea, but this had yet to be shown to change Pyongyang's calculus.

Zeng also said that Xi told Obama that he hoped Washington will play a constructive role in order to maintain peace and stability in the South China Sea dispute.

"The hope is that all parties will correctly view and handle the South China Sea and adopt an objective and impartial attitude ... particularly countries outside this region," he said.

Obama, speaking after an earlier meeting with the leaders of Japan and South Korea, said the three countries shared a common vision for the Asia-Pacific based on "a rules-based order in which all countries, regardless of size, act according to shared norms and shared principles."

The United States and South Korea agreed to begin talks on possible THAAD deployment last month after North Korea tested its fourth nuclear bomb on Jan 6 and launched a long-range rocket on Feb 7.

Apart from these developments, China's Defence Ministry announced on Thursday it has set up a dedicated unit to coordinate its "non-war" activities overseas like evacuations from conflict zones, as it seeks to play a greater role in the world.

China last year passed a counter-terrorism law that allows the military to venture overseas on anti-terror missions, though experts have said it would face big practical and diplomatic problems if it ever wanted to do this.

"We've had good support from China, but we clearly believe that there's more that will continue to have to be done, including on enforcing the sanctions we have put into place," Rhodes told reporters.