Venezuela is being added to the list of countries "not fully cooperating" with U.S. government anti-terrorism efforts and will face a ban on U.S. arms sales to that nation, a State Department official said on Monday.

For nearly a year, there has been a nearly total lack of cooperation with anti-terrorism, said Darla Jordan, a State Department spokeswoman.

This move is highly unusual since the other nations on this list — Cuba, Iran, North Korea and Syria, for instance — are also on the "state sponsor of terrorism" list, and Venezuela is not.

The designation means the U.S. government prohibits all commercial arms sales and licensing of defense articles and services to the government of Venezuela. The designation for Venezuela applies only to military issues. That is different from state terror sponsor sanctions in that those nations frequently face bans on U.S. citizens spending money in those nations or other financial transactions.

Jordan said Venezuela has been providing a safe haven for the two main leftist guerrilla groups in Colombia. Last month, the State Department issued an annual report on international terrorism in which it accused Venezuelan President Hugo Chavez of having an "ideological affinity" with terrorist-designated groups FARC and the National Liberation Army.

Venezuela is a major supplier of oil to the United States but relations between Chavez and the Bush administration have sharply deteriorated. Chavez has called Bush a "terrorist," and denounced the U.S.-led war in Iraq.

Earlier Monday, Chavez rejected U.S. claims that Iran's nuclear program is aimed at producing a nuclear bomb. "I don't believe that the United States or anyone else has the right ... to prohibit that a country has nuclear energy," he said at a news conference in London.

Chavez, an ally of Cuba's Fidel Castro, has repeatedly accused the United States of trying to overthrow him to seize his country's vast oil reserves. U.S. officials have denied that and accused him being a threat to democracies in the region.

Hearing about the ban, Chavez said his government will not respond with travel restrictions or other punitive measures. He called the United States an "irrational empire."

"This doesn't matter to us at all," he said. "It's the empire and it has a great capacity to do harm to the countries of the world."

House Intelligence Committee Chairman Pete Hoekstra, R-Mich., said Venezuela's lack of support in fighting terror "comes as little surprise."

"The hostility shown by the Venezuelan leadership towards the United States along with its efforts to sow totalitarianism in the hemisphere, at the expense of the Venezuelan people, should be alarming to everyone. We must remain vigilant against Venezuela's efforts to spread anti-Americanism in Central and Latin America and the opening it provides for terrorists seeking to operate in our own backyard," Hoekstra said.

FOX News' Teri Schultz and The Associated Press contributed to this report.