US Secretary of State Hillary Clinton and a Chinese official acknowledged "good progress" had been made when they talked about efforts to impose new sanctions on Iran, a US official said Wednesday.

State Department spokesman Philip Crowley said Clinton and China's state councilor Dai Bingguo spoke for more than an hour by telephone late Tuesday, discussing both Iran and North Korea, whose nuclear programs worry Washington.

"They talked about the status of discussions on Iran sanctions. They acknowledged that good progress has been made," Crowley told reporters.

They discussed "a couple of technical issues in the drafting... of the draft (UN sanctions) resolution and pledged that both sides would continue to work hard within the P5-plus-1 to resolve remaining questions," Crowley said.

He was referring to the permanent five members of the UN Security Council -- the United States, China, Russia, France and Britain -- plus Germany, or the group that is spearheading diplomatic efforts to curb Iran's nuclear ambitions.

He added that diplomats from the P5-plus-1 met earlier Wednesday in New York, the site of the UN headquarters.

On April 22, US Vice President Joe Biden said that China will sign on to new United Nations sanctions on Iran despite Beijing's long insistence in favoring a diplomatic solution over punitive measures.

Washington has been trying to persuade China for months to accept toughened sanctions. Beijing has agreed to join talks at the UN on a toughened regime, but has yet to make its position clear.

Meanwhile, Crowley said Dai briefed Clinton on a visit to China last week by North Korean leader Kim Jong-Il, which come on top of briefings Chinese officials earlier gave senior US diplomats about the visit.

Dai "gave the secretary a little more insight into the recent visit to Beijing by Kim Jong-Il," Crowley said without elaborating.

Pyongyang's official media on Saturday reported that Kim said the isolated Stalinist state remains committed to nuclear disarmament, a year after quitting six-party talks on its atomic arsenal.

North Korea, which has tested two nuclear bombs, last year bolted from six-nation talks involving North Korea and South Korea, China, the United States, Russia and Japan.