TEHRAN, Iran, (AP) – The head of Iran’s atomic agency said the Islamic Republic would not enrich uranium to a higher level if the West provides the fuel it needs for the Tehran research reactor.

Iran is set to start enriching its stockpile of uranium to 20 percent on Tuesday, in a move sure to antagonize Western nations who fear that the process of enrichment could eventually yield material for a nuclear weapon.

France and the U.S. said Monday the latest Iranian move left no choice but to push harder for a fourth set of U.N. Security Council sanctions to punish Iran’s nuclear defiance.

Ali Akbar Salehi, a vice president as well as the head of the country’s nuclear program, said the further enrichment would be unnecessary if the West found a way to provide Iran with the needed fuel.

“Whenever they provide the fuel, we will halt production of 20 percent,” he told the state TV late Monday, referring to the enrichment of the country’s stockpile above its current level of 3.5 percent.

Uranium enriched up to a level of 90 percent can be used to make nuclear weapons and the West fears that Iran’s enrichment program is ultimately geared toward military purposes. A charge Iran denies.

On Tuesday, the spokesman of Iran’s Foreign Ministry, Ramin Mehmanparast told reporters the higher enrichment will be done with the cooperation and supervision of the U.N. nuclear watchdog adding that “if other countries or the agency could provide the fuel, our attitude can be different as well.”

Mehmanparast said any plan by the West to impose new U.N. Security Council resolutions would not be useful.

“If they attempt another resolution, they are making a mistake. It is not helpful in resolving the nuclear dispute between Iran and the West,” he said. “They are completely wrong if they think our people will back down even a single step.”

Pentagon spokesman Geoff Morrell said U.S. Defense Secretary Robert Gates believed the United Nations should slap new sanctions on Iran in “weeks, not months.”

Morrell said Gates believes a U.N. resolution would lay the legal groundwork countries need to impose sanctions independently and pressure Iran to abandon its nuclear program.

No new U.N. Security Council sanctions can be passed, however, without unanimous agreement from all members, including China who has been reluctant to impose new punitive measures on Iran.

China called for more talks on Tuesday, with Foreign Ministry spokesman Ma Zhaoxu saying “I hope the relevant parties will step up efforts and push for progress in the dialogue and negotiations.”

Turkish Foreign Minister Ahmet Davutoglu said he would travel to Tehran either tonight, or on his return from a trip to Kazakhstan on Feb. 12, for talks on the nuclear issue, saying he was “optimistic that there is still a common ground.”

“I believe that diplomatic channels are not exhausted and the door for chance (for a solution) is still open,” he said.

Salehi said Iran has been trying to buy the higher enriched fuel for its research reactor for the past several months, but the West tied providing the fuel with a U.N.-drafted agreement to ship Iran’s stockpile abroad first.

He said Iran would begin 20 percent enrichment on Tuesday by injecting gas into a cascade of centrifuge machines. Salehi said Iran needs some 1.5 kilograms of 20 percent enriched uranium a month for the Tehran research reactor to produce medical isotopes.

Salehi said 164 centrifuge machines were ready in a laboratory in Natanz to produce three to five kilograms of higher enriched uranium per month.

The official said the laboratory is on ground floor of the plant while enrichment facilities are underground. Salehi said inspectors from the International Atomic Energy Agency are expected to be present when Iran begins the higher enrichment.

“The agency continues to have inspectors in Iran conducting normal safeguards operations,” IAEA spokeswoman Gill Tudor said Tuesday when asked if they would be present.

Iran says it needs the 20 percent enriched fuel for a research reactor producing radio isotopes to treat cancer and manufacture radiography materials. Iran says more than 850,000 people need the products for their illnesses.

Iran purchased 116 kilograms of the fuel in 1987 from Argentina, through the IAEA.

Before 1979 Islamic revolution when Iran and the U.S. had close ties, the U.S. provided fuel to the reactor in 1967.

The center has also an educational role in training of Iranian researchers on nuclear issues.