Updated

North Korea will have no choice but to ultimately return to six-nation nuclear disarmament talks, the U.S. said Sunday, buoyed by a U.N. Security Council resolution sanctioning Pyongyang for launching missile tests.

The talks — involving China, North and South Korea, Japan, Russia and the United States — have been stalled since September, and North Korea has not agreed to return.

"I think ultimately North Korea will have no choice but to return to the talks and pursue denuclearization of the Korean peninsula," U.S. Secretary of State Condoleezza Rice told reporters at the Group of Eight summit in St. Petersburg.

The Security Council demanded Saturday that North Korea, which recently test-fired missiles, suspend its ballistic missile program. The resolution bans all U.N. member states from selling material or technology for missiles or weapons of mass destruction to North Korea, and from receiving missiles, banned weapons or technology from Pyongyang.

CountryWatch: North Korea

North Korea swiftly rejected the sanction and warned that the resolution was a prelude to a renewed Korean war.

But the White House shrugged off North Korea's rejection of the Security Council's decision Sunday, and Rice warned that world powers could bring additional pressure against North Korea.

"It's probably not surprising that they have immediately rejected it," said Dan Bartlett, U.S. President George W. Bush's senior counselor. "But sometimes the first response is not the only response or the final response. But what it says is that the world is speaking with one voice."

Pyongyang also said it would "bolster its war deterrent for self-defense," a typical phrase often used by the reclusive communist nation to refer to the country's nuclear weapons program.

"Our republic vehemently denounces and roundly refutes the 'resolution,' a product of the U.S. hostile policy towards the DPRK, and will not be bound to it in the least," the Foreign Ministry said in a statement carried by North Korea's official Korean Central News Agency. DPRK stands for the Democratic People's Republic of Korea.

Prominent Russian legislator Konstantin Kosachev said it was important to separate the issue of North Korea's nuclear program and its political regime.

"If we are able to convince North Korea that there won't be any forceful attempts of toppling the regime, I think we will be able to make major progress on the issue of its nuclear program," said Kosachev, who has close links to the Kremlin.

Rice warned that North Korea could face additional action.

"If they do not want to face some of the additional pressures that can be brought to bear on them," she said, "then I think that they will eventually realize that they've got to come back to the six-party talks. That's really the only game in town."

Rice praised the Security Council resolution and expressed particular pleasure that China had voted for it. China is believed to have more influence on North Korea than any other country and has been reluctant to impose sanctions on North Korea.

She said the multiparty talks are "really paying off. Because we really now have a coalition."

On Sunday, Bush and Chinese President Hu Jintao met in a villa on the grounds of the palace where summit talks are being held and pledged to work together to defuse the crises with North Korea and Iran.

"Both parties expressed their commitment to maintain peace and stability on the Korean peninsula," Hu said.

Hu said they also would work together on a peaceful solution to the nuclear showdown with Iran.

Bush thanked Hu for China's support of the U.N. Security Council resolution imposing sanctions on North Korea, and for working together on Iran.

Both men said they also discussed economic, trade and other issues.