The United States said Friday it was monitoring Venezuela's ties to Iran and "no option" is off the table for potential sanctions against President Hugo Chavez's government in Caracas.

Kevin Whitaker, the acting deputy assistant secretary for Western Hemisphere affairs, said Washington was monitoring Venezuela for "patterns of support for acts of international terrorism."

"No option is ever off the table, and the department will continue to assess what additional actions might be warranted in the future," he told a congressional hearing.

"The department strongly urged Venezuela to pursue a path of cooperation and responsibility rather than further isolation and we will continue to do so."

Venezuela's Foreign Minister Nicolas Maduro shot back, saying the US threats only stoke Venezuelan patriotism.

The United States slapped sanctions on Venezuela's state oil giant and cash cow PDVSA on May 24 for its commercial ties to Iran, which Washington deems in violation of international sanctions over its nuclear program.

"All this did was just create a wave of patriotic sentiment and international solidarity, while PDVSA is growing and consolidating. Any threat they make strengthens us as a country," he told reporters.

"There are no extremist fascists in the world who can threaten our homeland. We are prepared to engage with countries we consider useful partners."

The State Department's coordinator for counterterrorism, Daniel Benjamin, told the hearing convened by Republicans in the US House of Representatives that Venezuela has shown a "demonstrable failure" to meet international requirements, particularly in counternarcotics operations.

"Instead of meeting its international obligations," Venezuela "has chosen to have close relations with Iran and Syria," Benjamin said.

Adam Szubin, director of the Office of Foreign Assets Control, which oversees international sanctions, meanwhile told lawmakers that Washington would "persist in investigating activities implicating Venezuela," adding "we will not hesitate to take actions" against Caracas if required.

Representative Connie Mack of the House Foreign Affairs Committee called for stiffer, immediate action, insisting that Caracas be deemed a "state sponsor of terrorism," a designation US authorities make against Cuba, Iran and Syria.

Maduro labeled the Florida Republican a "crazy right-wing fascist" for his efforts.

Iranian officials have staunchly denied Western suspicions that Tehran's nuclear enrichment program is masking a drive for atomic weapons.

Hardline Iranian President Mahmoud Ahmadinejad insisted Thursday that Iran is not seeking to build an atomic weapon but defiantly added that should it decide to do so "no one can do a damn thing."