Obama: A Nuclear-armed North Korea Poses A Grave Threat to the World

U.S. President Barack Obama said on Tuesday that a nuclear-armed North Korea poses a "grave threat" to the world.

Speaking at a joint news conference in the White House with South Korean President Lee Myung-bak, Obama vowed to end a cycle of allowing Pyongyang to create a crisis and then be rewarded with incentives to back down.

"There's been a pattern in the past where North Korea behaves in a belligerent fashion and if it waits long enough is then rewarded with food stuffs and fuel and concessionary loans and a whole range of benefits and I think that's the pattern that they've come to expect. The message we are sending, and when I say we, not just the United States and the Republic of Korea, but I think the international community is - we are going to break that pattern."

Both Obama and Lee Myung-bak reaffirmed their commitment to the complete denuclearization of the Korean peninsula.

Lee said the international community would not respond to North Korean provocations, such as additional underground nuclear tests, by offering financial incentives.

"As reiterated by President Obama we agreed that under no circumstance are we going to allow North Korea to possess nuclear weapons. We also agreed to robustly implement United Nations Security Council Resolution 1874 and of course all parties will faithfully take part in implementing this resolution."

Lee added that his country, along with the United States, Japan, China and Russia, would seek new measures designed to compel North Korea to dismantle its nuclear weapons program.