TEHRAN, Iran – In defiant swipes at its foes, Iran said Wednesday it is dramatically closer to mastering the production of nuclear fuel even as the U.S. weighs tougher pressures and Tehran’s suspected shadow war with Israel brings probes far beyond the Middle East.

Iran further struck back at the West by indicating it was on the verge of imposing a midwinter fuel squeeze to Europe in retaliation for a looming boycott of Iranian oil, but denied reports earlier in the day that six nations had already been cut off.

The uncompromising messages from Iran, however, came with a counterpoint. The official IRNA news agency said Iran’s top nuclear negotiator, Saeed Jalili, told European Union foreign policy chief Catherine Ashton that Iran is ready to return to talks with the U.S. and other world powers.

The dual strategy – taking nuclear steps while proposing more talks – has become a hallmark of Iran’s dealings for years and some critics have dismissed it as a time-buying tactic.

The advances claimed Wednesday could likely feed these views.

In a live TV broadcast, President Mahmoud Ahmadinejad was shown overseeing what was described as the first Iranian-made fuel rod inserted into a research reactor in northern Tehran. Separately, the semiofficial Fars agency reported that a “new generation” of Iranian centrifuges – used to enrich uranium toward nuclear fuel – had gone into operation at the country’s main enrichment facility at Natanz in central Iran.

In Washington, the assistant secretary of state for International Security and Nonproliferation, Tom Countryman, dismissed the Iranian claims of reaching a pivotal moment.

“The announcement today by Iran has much more to do with political developments in Iran than it has to do with factual developments,” he said.

White House press secretary Jay Carney said Iran’s “defiant acts” seek to “distract attention” from the damage brought by international sanctions.

Meanwhile, Iran is facing major new international complications: Accusations of bringing an apparent covert conflict with Israel to points stretching from Thailand and India to the former Soviet republic of Georgia.

Officials in Israel ramped up allegations that Iran was linked to international bomb plots, saying magnetic “sticky” bombs found in a Bangkok house rented by Iranians were similar to devices used against Israeli envoys in a foiled attack in Georgia on Monday and a blast in New Delhi that injured four people, including a diplomat’s wife.

“In recent days, Iran’s terror operations are being laid bare for all,” said Israeli Prime Minister Benjamin Netanyahu, who convened his security cabinet. It included discussions about “preventive measures” against Iranian threats, said a statement from Netanyahu’s office that did not elaborate.

Iran’s Foreign Ministry spokesman, Ramin Mehmanparast, called the allegations “baseless” and an attempt to push “conspiracy” theories to discredit Iran with its Asian partners, including major oil buyer India.