BERLIN (Agencies) -- A meeting of European, Russian, Chinese and U.S. officials in London on Monday did not produce a full consensus on how to proceed with Iran over its nuclear program, a senior German diplomat said on Tuesday, Reuters reported.

German Deputy Foreign Minister Gernot Erler, speaking on German public television, confirmed that agreement had been reached to convene an extraordinary meeting of the International Atomic Energy Agency (IAEA) in Vienna on Feb. 2.

But he said there were still disagreements among the countries that met in London over the content of a planned resolution referring Iran to the UN Security Council and what the goal of such a resolution should be. "We remain in talks about what should be decided there and what the role of the United Nations should be," Erler said.

"That is a sign that we could not reach a full agreement what the goal of the IAEA is through a resolution but that more time is needed."

Erler added that it remained important to seek a diplomatic solution to the impasse over Iran's nuclear program.

Russian President Vladimir Putin on Monday warned against "abrupt, erroneous steps" toward Iran.

Russia, China want talks not sanctions on Iran

"The Chinese government believes that peacefully resolving the Iranian nuclear issue through diplomatic negotiations is a good option under current circumstances and is in the interests of all parties," a spokesman for China's foreign ministry, Kong Quan, told reporters in Beijing at a regular briefing.

China's ambassador to the United Nations, Wang Guangya, made a more pointed call in New York on Friday, saying that taking Tehran to the Security Council "might complicate the issue".

China is one of the permanent members of the Security Council that can wield a veto over any proposals. The others are the United States, France, Britain and Russia.

Kong, the spokesman, said Wang's comments did not differ from China's official position, but did not directly address questions about whether China will reject any attempt by the United States or European Union to refer Iran to the Security Council.

Sanctions 'not best' option on Iran: Russian FM

Sanctions are not the best way to resolve the Iranian nuclear issue, Russian Foreign Minister Sergei Lavrov said in Moscow on Tuesday, AFP reported.

The use of sanctions is "not the best and by no means the only way to resolve international problems," Lavrov told journalists with reference to Iran.

While cautioning against sanctions, he urged Iran to do more to cooperate with the IAEA.

"First of all we should be doing our utmost for the IAEA to professionally collect the maximum amount of information... to help us answer the questions we have about the past of the Iranian nuclear program," Lavrov said.

"Iran should do much more than it has done. Certain progress has been achieved in clarifying dark spots, but more is required of Iran," he said.

Lavrov also said that any resumption of negotiations between Iran and the "EU-3" had to be preceded with a return by Tehran to a voluntary moratorium on nuclear research.

Lavrov's comments came as Iran vowed to put an end to tough UN inspections of its atomic program and fully resume nuclear fuel work if its case is referred to the Security Council.

Iran's ambassador to the IAEA, Ali Asgar Soltaniyeh, also told the student news agency ISNA that a decision to kick-start nuclear research work was "irreversible".

"As I said recently, if Iran's nuclear case leaves the framework of the IAEA for the Security Council, the government -- in line with the law voted by parliament -- will end voluntary cooperation," he was quoted as saying.

He said this included an end to a voluntary suspension of certain nuclear fuel work.

While Iran has restarted uranium enrichment research it is for now maintaining a freeze on large-scale enrichment work.

UK aims for diplomatic solution to Iran impasse

Britain said on Tuesday it still aimed for a diplomatic resolution to the standoff between Western powers and Iran over its nuclear program, Reuters reported.

"Our ideal outcome is a diplomatic solution. This has to mean Iran abides by its international obligations -- that is the test," Prime Minister Tony Blair's spokesman told reporters.

"If Iran wants to come up with a solution that meets that test, it is all well and good."

He declined to say whether Russia and China have signaled they would support a referral of Iran to the UN Security Council.

"The fact that the IAEA meeting has been brought forward by a month speaks for itself. Everyone senses a great deal of urgency to deal with this issue," said the spokesman.

"Fatalism does not characterise our approach."

"We don't see this leading straight into sanctions," A British foreign ministry official told reporters under condition he not be named.

"We want to build gradual, sustained pressure over time. We are not going to New York to impose punitive economic sanctions."

He said Russia and China had not yet decided whether to back a proposal to refer Iran's case to the council.

He dismissed reports that Iran had invited Britain, France and Germany to resume talks, adding that the EU trio had cancelled a meeting with Iranian officials planned for Wednesday.

"That is vacuous, because the Iranians have created the conditions to make (further talks) impossible," he said.