Russia has brought home its contingent of technicians and engineers working on Iran's unfinished nuclear reactor plant at Bushehr as mounting international pressure piles up on Tehran, Austria Press Agency (APA) reported Tuesday.

The move would facilitate the enforcing of harsher UN sanctions against Iran, which further refused to halt uranium enrichment last month, the report said.

Many Russian experts had departed for Moscow last week, a move thought likely to have been triggered by financial disputes between Russia and Iran.

Sergei Novikov, spokesman for Russia's federal nuclear power agency Rosatom, confirmed the reason had been Iranian payment delays.

Russia also denied a report by The New York Times that Moscow had threatened to withhold fuel for the Bushehr power plant should Iran still stonewall Security Council demands to suspend its uranium enrichment program.

The New York Times, citing unnamed European, American and Iranian officials, had cited an ultimatum given last week by Igor Ivanov, head of the Russian National Security Council, to Ali Hosseini Tash, Iran's deputy chief nuclear negotiator.

"I can tell you that the report is not accurate, that there has been no Russian ultimatum to Iran of any kind," Russian Ambassador to the UN, Vitaly Churkin, told reporters.

"We continue to regard the Bushehr project as being an issue outside the scope of Resolution 1737, and of that of the draft resolution currently being worked on in New York. The Bushehr project is a separate economic project."

The UN Security Council will hold formal consultations today on a draft resolution prepared by Britain, China, France, Russia, the United States and Germany as to stronger sanctions against Iran.

Iranian President Mahmoud Ahmadinejad is set to address the 15-member Security Council to defend his country's nuclear ambitions on the day of the vote.

(Xinhua News Agency March 21, 2007)