U.S. President Barack Obama made a surprise appearance at a meeting between Chinese Foreign Minister Wang Yi and U.S. National Security Advisor Susan Rice, the White House said Wednesday.

The meeting between Wang and Rice was watched closely as the two sides were expected to reach a final agreement on a draft U.N. Security Council resolution imposing sanctions on North Korea for its nuclear and missile tests.

The two sides "agreed on the importance of a strong and united international response to North Korea's provocations, including through a U.N. Security Council Resolution that goes beyond previous resolutions," the White House said in a statement.

"They agreed that they will not accept North Korea as a nuclear weapons state," it said.

The White House said that Obama's attendance at the meeting underscores "his interest in building a durable, constructive and productive U.S.-China relationship."

"He expressed the importance of the upcoming Nuclear Security Summit in Washington, D.C., on March 31-April 1, 2016," the White House said. "He noted he looked forward to welcoming President Xi and China's delegation to the summit and to working together towards its success."

During the meeting, Rice and Wang also affirmed their commitment to expanding practical bilateral cooperation while also addressing and, where possible, narrowing differences, and highlighted important areas of ongoing bilateral cooperation, including climate change and the implementation of the Iran nuclear deal.

They also candidly discussed maritime issues, it said. (Yonhap)