Seoul, South Korea (CNN) -- South Korea has accepted a North Korean proposal for high-level military talks and will propose working-level talks to pave the way, South Korea's defense ministry said Thursday.

In the preparatory talks, the South will demand that Pyongyang take responsibility for last year's military provocations, the ministry said. High-level talks will only be held if the North promises to refrain from further provocations.

The date and time of the talks have not yet been determined, according to a ministry media officer. Such officers customarily do not give their names.

The Seoul government also decided to propose holding inter-Korean talks between high-ranking government officials to discuss denuclearization, according to South Korea's Yonhap news agency.

The announcement came a day after China, North Korea's main ally, acknowledged the possible existence of Pyongyang's nuclear enrichment program, and Chinese President Hu Jintao said he and U.S. President Barack Obama agreed to work together on denuclearizing the Korean peninsula.

"The United States and China expressed concern regarding the DPRK's (North Korea's) claimed uranium enrichment program," said a joint U.S.-China statement after Hu and Obama met Wednesday in Washington.

Later, Hu told reporters that China and the United States would "work with the relevant parties to maintain peace and stability on the peninsula, promote denuclearization of the peninsula and achieve lasting peace and security in Northeast Asia."

White House Press Secretary Robert Gibbs said Thursday that the joint statement and Hu's comments signaled South Korea that China was now aligned with the United States in opposing North Korea's nuclear weapons program.

"I think some of that comes as a result of yesterday's meeting here that for the first time there was an acknowledgment by the Chinese about the North Koreans' enrichment program," Gibbs said. "I think following that, the Republic of Korea agreed to enter talks with the North Koreans. Clearly conditions were created yesterday that showed the Republic of Korea that China and United States were aligned in dealing with the aggressions of the North Koreans. I think it is clearly a positive step."

Earlier this month, South Korea's Ministry of Unification said it had reopened communication channels with North Korea in the border area of Panmunjom.

The direct hotline was reopened between the two Koreas and Red Cross communication channels, the ministry said.

It was the first time in eight months the two sides have reopened the hotline. North Korea cut the hotline off on May 26 to protest Seoul's response to the March sinking of the South Korean naval ship Cheonan. Forty-six sailors died. South Korea has blamed North Korea for the sinking, which Pyongyang has denied.

Tensions rose again in November, when North Korea shelled South Korea's Yeonpyeong Island, killing two South Korean marines and two civilians. North Korea said the strike was in response to the South's navy firing into Northern waters.

CNN's Jiyeon Lee contributed to this report