The refusal, announced Friday on state television by Iran's nuclear chief, indicated a sudden hardening of Iran's attitude toward the International Atomic Energy Agency. A day earlier, Iran had said it welcomed the comments of the IAEA board meeting in Vienna and earlier this week said it was "studying positively" an IAEA report on Iran.
The head of the IAEA, Mohamed ElBaradei, had called Monday for Iran to allow the agency "to take environmental samples at the particular location where allegations about enrichment activities exist."
Agency inspectors were turned away from a site at Kalaye, west of Tehran, last week after they came to take environmental samples. Iranian officials have never publically disclosed what the Kalaye site is used for, but the country is suspected of testing nuclear centrifuges there.
In its nightly news bulletin Friday, Iranian television said the head of Iran's Atomic Energy Organization, Gholamreza Aghazadeh, would not permit environmental sampling at "some locations." It did not name the locations.
"This is contrary to agreements signed (between Iran and the IAEA) and we will not allow this," Aghazadeh said.
"We've had no problem concerning environmental samples, but we've been telling the IAEA that this location is not a nuclear location, so that if you want take environmental samples, this is outside the framework of the protocol," Aghazadeh said. He did not identify the location.
"If we accept to operate outside the framework of the protocol, it will have no ending ... and tomorrow ten other locations may be named," said Aghazadeh, who was shown speaking to a state television reporter.
The United States suspects Iran is trying to build a nuclear bomb — a charge Iran denies. The U.S. delegation to the IAEA has pushed for the agency to declare Iran in violation of the Nuclear Nonproliferation Treaty.
In Moscow, Russian President Vladimir Putin said Friday Iran was not trying to make nuclear weapons and he warned against pressuring Russia to end its nuclear cooperation with Iran.
Putin said Iranian President Mohammad Khatami had assured him in a telephone call two days ago that his country is not seeking to develop nuclear weapons and that it was prepared to sign any protocols required by the IAEA.
"The Iranian leadership is ready to fully meet all the IAEA demands regarding control over its nuclear program," Putin said.
At the end of a four-day board meeting in Vienna on Thursday, the IAEA urged Iran to stop enriching nuclear fuel and to allow greater access to its nuclear facilities.
The IAEA said it expected Iran "to grant the agency all access deemed necessary" to defuse suspicions Tehran is operating a clandestine nuclear weapons program.
Aghazadeh did not respond Friday to the IAEA demand for a cessation of uranium enrichment.
IAEA inspectors are expected to return to Iran next month in what will be the first test of Tehran's willingness to comply with the agency's requests.
"I trust, I expect, that Iran will enable us to do all that we need to do," ElBaradei said during this week's board meeting.
Iran says its nuclear program is designed solely to produce electrical energy, particularly after its oil wells run dry.
At the European summit in Porto Carras, Greece, EU leaders said Friday they were "seriously concerned" about the nuclear programs of Iran and North Korea.
In a final statement, the leaders called on Khatami to make good his commitment to "full transparency" on Iran's nuclear program.
In London, the U.S. undersecretary of state for arms control, John Bolton, said U.S. President George W. Bush was not considering military action to stop Iran from developing nuclear weapons, but force remained an option.
"The president has repeatedly said that all options are on the table. But that is not only not our preference, it is far, far from our minds," Bolton told British Broadcasting Corp. radio on Friday.