Beijing: Tehran's top nuclear negotiator met senior officials in Beijing for a second day Friday as US reports said China had dropped its opposition to possible new UN sanctions against Iran over its nuclear program.

Saeed Jalili met Wang Jiarui, who heads the Communist Party's international affairs office, a day after China sidestepped questions on whether it had changed its traditional opposition to new sanctions.

China has veto power in the UN Security Council, and its support would be key to passing a resolution against Iran, which is suspected of developing nuclear weapons. Tehran says its nuclear program is for peaceful power generation.

Jalili, who met Foreign Minister Yang Jiechi on Thursday, was scheduled to give a news conference later Friday.

US President Barack Obama raised the issue of Iran's nuclear program when he spoke on the phone for an hour Friday with his Chinese counterpart Hu Jintao, welcoming his decision to attend a nuclear security summit in Washington in less than two weeks.

"Obama underscored the importance of working together to ensure that Iran lives up to its international obligations," a White House statement said.

On Thursday, Foreign Ministry spokesman Qin Gang would not confirm reports that China was willing to consider new sanctions, saying only that it was "concerned about the current situation."

Qin repeated Beijing's longtime stance of wanting the dispute settled through negotiations.

China depends on oil- and gas-rich Iran for 11 percent of its energy needs and last year became Tehran's biggest trading partner, according to Iranian figures.

China traditionally opposes sanctions. Although it went along with three earlier UN sanctions resolutions against Iran, Beijing has been a vocal opponent of a fourth round, insisting that further negotiations with Tehran were needed.

But US officials say a Chinese representative made a commitment in a phone call Wednesday with officials of the US, Russia, China, Britain, France and Germany to discuss specifics of a potential Security Council resolution, and that on that basis the US would press ahead with an effort to pass such a measure.

The officials cautioned that this does not mean there is a full consensus yet on UN sanctions. The officials spoke on condition of anonymity because the diplomatic talks were ongoing.

The Obama administration is hoping to get a UN resolution on Iran passed by the end of April.

According to well-informed UN diplomats, speaking on condition of anonymity because the discussions are taking place among capitals, the proposed new sanctions would target Iran's powerful Revolutionary Guard and toughen existing measures against Iran's shipping, banking and insurance sectors.