President Barack Obama met with Chinese president Hu Jintao Monday on the sidelines of a 53-nation Nuclear Security Summit in Seoul.
The two leaders were expected to discuss bilateral issues, including the state of nuclear weapons programs in Iran and North Korea.
In remarks Sunday, Mr. Obama urged China to stop turning a blind eye to North Korea's nuclear defiance and use its influence to rein in Pyongyang's nuclear ambitions. China is North Korea's main ally and trading partner, but Beijing says its political influence over Pyongyang is limited.
In a speech at Hankuk University in Seoul earlier Monday, Mr. Obama warned Pyongyang that it could continue down the road it is on, but that would lead to more broken dreams, more isolation and ever more distance between the people of North Korea and the dignity and opportunity they deserve.
Mr. Obama said ahead of a meeting Monday with the Russia president that he would discuss a diplomatic resolution to the situation.
Although it is not on the agenda of the formal summit, North Korea's recent announcement that it will launch a satellite into space using a long-range rocket has captured the attention of the assembled leaders. The North says this is part of celebrations marking the 100th anniversary of the April 15 birth of its late founder and president, Kim Il Sung.
The U.N., U.S., European Union, Russia and Japan have warned North Korea that its scheduled rocket launch is in violation of U.N. resolutions, and they have urged Pyongyang to abandon the plan. Even North Korea's ally China has expressed concern that a launch would undermine stability in the region.
The United States has said the launch would cancel an agreement to send North Korea a large shipment of U.S. food aid in exchange for halting its nuclear and long-range missile programs.
Ahead of the summit, U.S. officials announced that Ukraine has completed the removal of a consignment of highly enriched uranium, which can be used to make nuclear bombs. The material, Russian in origin, has been sent back to Russia. VoA.