Tokyo  - US President Barack Obama Saturday called for North Korea to return to denuclearization talks, urging it to choose "international integration" over "isolation that has compounded the horrific repression of its own people."

Obama was speaking to Japanese citizens, scientists and business people at Suntory Hall in Tokyo, a day after meeting with Japanese Prime Minister Yukio Hatoyama as part of his seven-day tour of Asia.

The US, Japan, China, Russia and South Korea have been engaged in six-party talks with North Korea for years to convince Pyongyang to disband its nuclear weapons programme.

After Pyongyang tested another nuclear device earlier this year, the UN Security Council passed the most sweeping sanctions to date against the Stalinist state. But North Korea has been reluctant to return to the talks.

"We will not be cowed by threats, and we will continue to send a clear message through our actions, and not just our words: North Korea's refusal to meet its international obligations will lead only to less security - not more," Obama said.

Obama repeated past assurances from Washington that the US was prepared to offer North Korea a "different future" of economic opportunity, with trade, investment and tourism giving the people of North Korea a "chance at a better life."

In his speech, Obama also saluted China for its growing role and responsibility on the world stage, saying the US was seeking "pragmatic cooperation" with Beijing.

At the same time, he sought to calm worries that Washington's "deeper relationships with China" meant a "weakening of our bilateral alliances" in the Asia-Pacific region.

Obama declared Washington's intent to renew its active role in the Asian region after being "disengaged" in recent years, an apparent reference to his predecessor George W Bush's distrust of international organizations.

Obama is to meet Tuesday and Wednesday with Chinese President Hu Jintao in Beijing.

Later Saturday, Obama will meet with Japan's emperor and empress before departing for Singapore, where he will meet with the 10 leaders of the Association of South-East Asian Nations (ASEAN) on Sunday and participate in the annual summit of the Asia-Pacific Economic Cooperation (APEC) forum.

He plans to meet on the sidelines with Russian President Dmitry Medvedev in Singapore. (dpa)