Iranian President Mahmoud Ahmadinejad on Sunday ordered the production of higher-enriched uranium -- significantly beyond the levels of its regular nuclear fuel -- prompting the United States to renew threats of carefully targeted sanctions.

Ahmadinejad's instructions were followed by an announcement from the head of Iran's Atomic Energy Organization that Iran would alert the International Atomic Energy Agency on Monday of its plans to "start making 20 percent enriched fuel on Tuesday."

The official, Ali Akbar Salehi, did not elaborate in an interview with Arabic-language state television on how close Iran may be to reaching that goal.

Iran says it needs the higher-enriched fuel to operate a 41-year-old, U.S.-built reactor used for medical purposes, but Washington and its allies worry that the uranium enrichment is a precursor to making bombs.

The IAEA said in a November report that Iran had not gone beyond its declared maximum enrichment level of 5 percent. Analysts say Iran is not yet able to produce enough uranium enriched at 20 percent to supply the needs of the Tehran reactor, but that it may not be far away, either.

"Iran could have been preparing for a few months to make 20-percent material, in which case they could start the process of producing this material on Tuesday," said David Albright, a former weapons inspector and president of the Institute for Science and International Security in Washington. "Otherwise, on Tuesday they could start preparing to do so. We will have to wait and see what the IAEA says about what it knows and when they knew it."

 Analysts say that even with 20-percent enriched fuel, running the medical reactor would be extremely difficult because Iran is thought to lack the technology to turn the fuel into rods. But that fuel could ultimately be further enriched to 90 percent or more, the level needed for a weapon.

If Iran enriched all of its current stock of fuel, Albright said, the nation would need only a small facility of about 500 to 1,000 centrifuges "to produce enough weapon-grade nuclear material in a breakout strategy aimed at getting enough for a weapon in about six months. Such a plant would be extremely hard to find."

U.S. officials have been dissatisfied with Iran's reaction to attempts to negotiate over its enrichment program, and Defense Secretary Robert M. Gates said in Rome on Sunday that "there is still time for sanctions and pressure to work" against Iran.

Iran's leaders have given conflicting signals in recent days about whether they will accept a U.N.-brokered deal under which Tehran would hand over a stockpile of low-enriched uranium for processing outside the country. In exchange, Iran would receive higher-enriched uranium in the form of special fuel assemblies that would enable it to power the medical research reactor in Tehran, but not make bombs.

On Friday, Iran's foreign minister said that Tehran was "nearing a final agreement that can be accepted by all parties."

But Ahmadinejad's order on Sunday to Salehi to "please start the production of 20-percent enriched uranium" was a step in the opposite direction. U.S. and European officials said it appeared to confirm their suspicions that Iran is not serious about reaching a deal and is instead stalling for time.
Ahmadinejad immediately followed his order, broadcast on state television, by saying negotiations with the West over the proposed uranium swap are not over.

China throws kink into U.S.-led push for sanctions on Iran
"If they came and said, 'We will exchange without conditions,' then we will exchange," Ahmadinejad said. "If they say they will cooperate regarding the reactor and the medicines, we will say, 'Very well, we cooperate.' " During a visit to Rome for meetings with Italian leaders, Gates called Iran's actions "very disappointing" and appealed to other countries to present a united diplomatic front against Tehran.

The United States has been pressing members of the U.N. Security Council to impose harsher sanctions against Iran, but has met resistance from Russia and China.

Asked Sunday what kinds of sanctions the United States favored, Gates did not offer specifics but said measures targeting the Iranian government -- rather than the population at large -- "have the greater potential to achieve the objective."

"The international community does not want the people of Iran to suffer more hardship than absolutely necessary," he said.

Iranian officials were quick to separate Ahmadinejad's order to produce enriched uranium and the proposed swap.

"Ahmadinejad's order on enrichment of uranium to 20 percent necessary for the Tehran research reactor has no contradiction with fuel swapping. These two are not inconsistent," Ramin Mehmanparast, a Foreign Ministry spokesperson, told the semiofficial Fars News Agency on Sunday.