The United States on Monday voiced hope that North Korea would change course and improve its people's welfare after a delegation headed to China to discuss development of special economic zones.

North Korea's official media said that Jang Song-Thaek, the uncle of young supremo Kim Jong-Un and vice chairman of the National Defense Commission, went to China for the latest round of talks on developing two border islands.

State Department spokeswoman Victoria Nuland, echoing a line of Secretary of State Hillary Clinton, said that North Korean leaders including Kim -- who took power in December after his father's death -- faced a stark choice.

"They can open their country, come back into compliance (with international accords) and live in a place that respects human rights, respects the needs of their people," Nuland told reporters.

"Or they can keep up what they've been doing and continue to face isolation and continue to face misery. So we're hopeful that the new leadership will consider changing course because that's obviously what's in the best interest of the North Korean people and the best interest of peace and security," she said.

North Korea has one of the world's most rigidly controled economies and is desperately poor, although it has been considering economic projects during talks with China, its primary ally.

The United States on February 29 reached an agreement to provide badly needed food aid and to start mending relations with North Korea, but the deal quickly collapsed after Pyongyang defiantly tested a rocket.

Japan's Kyodo News and South Korea's Yonhap news agency reported Monday that senior US and North Korean officials met informally last month in New York in the first high-level contact since the April rocket launch.

Nuland said that the United States had "regular contact" with North Korea through Pyongyang's mission at the United Nations but that there were no "big breakthroughs." She declined to specify the date of the last meeting.

A senior US official said that the State Department did not want to announce the timings of contacts with North Korea for fear of raising false expectations of progress.