UNITED NATIONS -- The United States will submit a draft resolution to the United Nations Security Council Thursday that would expand sanctions against North Korea in the wake of Pyongyang's latest nuclear test and rocket launch, a spokesman for the U.S. mission to the U.N. said.

"We look forward to working with the Council on a strong and comprehensive response to the DPRK's latest series of tests aimed at advancing their nuclear weapons program," Kurtis Cooper, acting spokesperson for the U.S. mission, said in a statement late Wednesday night.

Earlier, U.N, diplomats told The Associated Press that the U.S. and China had agreed on the wording of such a resolution.

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The U.S. mission told CBS News' Pamela Falk the resolution will be put to a vote within several days.

One Security Council diplomat called the draft resolution "significantly substantive." Another said the draft had been circulated Wednesday to the three other permanent council members -- Russia, Britain and France. Both diplomats spoke on condition of anonymity because all discussions on the proposed resolution have been private.

Their comments follow a flurry of activity in Washington, including meetings between China's Foreign Minister Wang Yi and U.S. Secretary of State John Kerry on Tuesday, and with National Security Adviser Susan Rice on Wednesday afternoon.

National Security Council spokesman Ned Price said Rice and Wang 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."

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

Also on Wednesday, Kerry told a Congressional hearing, "We're on the brink of achieving a strong United Nations Security Council resolution."

North Korea started off the new year with what it claimed was its first hydrogen bomb test on Jan. 6 and followed that up with the launch of a satellite on a rocket on Feb. 7 that was condemned by much of the world as a test of banned missile technology.

Over the past 10 years, North Korea has conducted four nuclear tests and launched six long-range missiles, all in violation of Security Council resolutions.

South Korea's U.N. Ambassador Oh Joon has urged the Security Council to adopt "extraordinary" measures to make clear to the North "that it will no longer tolerate its nuclear weapons development."

The U.S., its Western allies and Japan, also pressed for new sanctions that go beyond the North's nuclear and missile programs. But China, Pyongyang's neighbor and supporter on the council, is reluctant to impose measures that could threaten the stability of North Korea and cause the country's economy to collapse.

Wang said Tuesday a new U.N. resolution alone cannot resolve the North Korean nuclear issue and that dialogue was needed.

He said China was urging a "parallel track" in which there were both talks on denuclearization -- the top priority of the United States -- and replacing the armistice that ended the 1950-53 Korean War with a formal peace treaty, a key demand of Pyongyang.

While the U.S. and China were discussing a new U.N. resolution, Washington took tougher steps of its own against North Korea, tightening sanctions and announcing it will hold formal talks with South Korea on deploying a missile defense system that China fears could be used against it as well North Korea.

South Korea and Japan have also announced new measures against Pyongyang.