In his first meeting with Chinese President Xi Jinping this year, U.S. President Barack Obama cautioned Beijing Monday against rushing to reconvene six-way talks on North Korea's nuclear program, with Pyongyang showing no concrete signs of changing its course, according to Obama's aide.

Obama also underscored the need for close coordination in sending a clear message that there should be denuclearization on the Korean Peninsula, Ben Rhodes, deputy national security adviser for strategic communications, told reporters via videoconference.

The press aide added "any discussions or dialogue among the six parties around the situation in North Korea needs to be based upon actions taken by North Korea, which has not yet demonstrated its willingness to come to the table seriously," Rhodes said.

Obama and Xi met bilaterally in The Hague, the Dutch seat of government, where the National Security Summit is underway.

Obama's request is viewed as representing some differences between Washington and Beijing over the pace of resuming the six-party talks, last held in December 2008. China is the host of the forum, also involving South Korea, Japan and Russia.

China apparently hopes to revive the negotiations at an early date. But the Obama administration is focused on testing Pyongyang's seriousness regarding dialogue.

The U.S. and China have maintained close cooperation between the two nations in putting pressure on Pyongyang, said Rhodes.

"But we, as an international community, need to continue to insist that North Korea abide by its obligations," he added.

Talking to Xi, meanwhile, Obama reiterated concerns over Beijing's unilateral establishment of its own air defense identification zone in the East China Sea in November, according to the White House official.

Obama also emphasized the need to reduce territorial tensions in the East and South China Seas, he said.

Obama and Xi, meanwhile, also talked about the U.S. first lady Michelle Obama's ongoing trip to China.

"Michelle had an opportunity to meet with a number of young people in China, and these kinds of person-to-person ties are extremely important," Obama said at the outset of the talks.

Although she played some table tennis there, Obama joked, it was not like the high-level "Ping Pong diplomacy" between the two nations in the 1970s.

Xi described her visit as a token of "friendship and exchange." (Yonhap)