By Kim Young-jin

U.S. President Barack Obama has extended sanctions against North Korea as it poses an "unusual and extraordinary threat,” the White House said Monday.

The move came as world leaders attending the G20 summit in Mexico intensified pressure on Pyongyang to curb its nuclear and missile programs following a provocative long-range rocket launch in April.

A presidential statement to Congress said the “existence and risk of proliferation of weapons-usable fissile material” and the behavior of the North Korean regime to destabilize the region “constitutes an unusual and extraordinary threat to the national security, foreign policy, and economy of the United States.”

The extension continues a state of national emergency toward the North as the region mulls how to nudge the regime now led by Kim Jong-un to improve its behavior.

In Los Cabos, Obama and Russian counterpart Vladimir Putin agreed over the unlikelihood of an imminent provocation and called on Pyongyang to adhere to its denuclearization commitments under the six-party talks, a report said.

“We do not believe that any actions will be taken on North Korea’s part that would lead to an escalation of tension on the Korean Peninsula,” the leaders said in a joint statement on the sidelines of the summit, according to RIA Novosti.

“As partners in the six-party negotiating process, we are ready to continue joint efforts to achieve the verifiable denuclearization of the Korean Peninsula in accordance with the joint declaration,” the statement said.

Possible resumption of the talks, which also include Seoul, Beijing and Tokyo, were scuttled by the North’s rocket launch that earned it toughened U.N. sanctions. The move also killed a deal with the U.S. under which the North stood to gain 240,000 tons of nutritional aid.

President Lee Myung-bak echoed the stance during a summit with Canadian Prime Minister Stephen Harper during which the leaders called on Pyongyang to halt its missile and nuclear programs and focus instead on quality of life issues.

The launch was seen as a test of ballistic missile technology but also a move for the twenty-something Kim to consolidate support following the death of his father Kim Jong-il last year.

While Washington and Seoul have left the door open for dialogue provided Pyongyang take concrete denuclearization steps, hope is low for an immediate resumption of the six-party talks. Analysts say such a development could expose Obama to criticism during his reelection campaign.