The leaders of Russia and Germany called on Iran to fulfill its international nuclear obligations Thursday, a day before a U.N. Security Council deadline for Iran to stop enriching uranium.

Russian President Vladimir Putin and German Chancellor Angela Merkel also told reporters Thursday in the Siberian city of Tomsk that the crisis over Iran's nuclear program could be resolved only through diplomacy.

CountryWatch: Iran

"It's still too early to run ahead and say what decision we might take together," he said. "The main thing is ... that whatever decision is taken is a consensus decision."

The head of U.N. nuclear watchdog, the International Atomic Energy Agency, will present a report Friday on Iran's implementation of the Security Council demand. Uranium enrichment can produce fuel for nuclear power or material for nuclear warheads.

If Iran does not comply, the Security Council is likely to consider punitive measures against the Islamic republic. Russia and China, however, have been reluctant to endorse sanctions.

Iran has thus far rejected the demand and issued its toughest warning on the issue Tuesday. Nuclear negotiator Ali Larijani said that if the Security Council imposes sanctions, Iran would stop cooperating with the IAEA and conceal its nuclear activities.

"Our position is clear and well known. We are for the nonproliferation of weapons of mass destruction," Putin said. "But we believe that Iran must have an opportunity to develop modern technologies and peaceful nuclear energy."

Earlier, Russian Foreign Minister Sergey Lavrov said the IAEA report should not be seen as an ultimatum for Tehran.

"The procedure for referring and examining the report is not an ultimatum," Lavrov said. "It has a working character and therefore, there is no time limit."

Merkel also called for a diplomatic resolution.

"We are very interested for the world community, as it has been from the start, to work together and show Iran that we want to work by diplomatic methods," she said. "But it is necessary for Iran to keep to the agreements that it has committed itself to."

"We are not talking about banning Iran from using nuclear energy for civilian goals, but it must keep to its obligations and agreements," Merkel added.

China's Foreign Ministry, meanwhile, stressed the need for restraint as the crisis reached a crucial stage.

"We hope the relevant parties can keep calm and exercise restraint so as to avoid moves that would further escalate the situation," said Foreign Ministry spokesman Qin Gang.

Qin said the problem can still be "resolved through dialogue and diplomatic means, which is the correct choice for all parties concerned."