The United States is going to be a bulwark against Iranian adventurism in the world, Vice President Dick Cheney said Sunday, adding that Iran is "fishing in troubled waters" by trying to get a foothold in Iraq.

Cheney said that the United States is working through the United Nations to put the brakes on Iran's nuclear pursuits, going through the U.N. Security Council to impose sanctions, but the administration will continue its U.S. military presence in the Gulf and work with allies to stop Iran from stirring up trouble in the region.

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"I think it's been pretty well-known that Iran is fishing in troubled waters, if you will, inside Iraq," Cheney said on "FOX News Sunday With Chris Wallace." "The threat that Iran represents is growing, it's multi-dimensional, and it is, in fact, of concern to everybody in the region."

On Sunday, the U.S. military in Baghdad said five Iranians arrested in northern Iraq last week were connected to an Iranian Revolutionary Guard faction that funds and arms insurgents in Iraq. Officials said the site where they were taken into custody had been described by various Iraqi officials as an Iranian liaison office, but it did not have diplomatic status as a consulate.

Click here to read more about the arrest of five Iranians in Iraq.

Iran's government denied the five detainees were involved in financing and arming insurgents and said they should be released.

Speaking in Jerusalem on Saturday, Secretary of State Condoleezza Rice, who is now in Jordan, said raids against Iranian targets in Iraq are part of broad efforts to confront Tehran's aggression.

National Security Adviser Stephen Hadley added that the United States has the authority to confront Iranians in Iraq because they "put our people at risk."

"We are going to need to deal with what Iran is doing inside Iraq," Hadley said on ABC's "This Week."

"[President Bush] said very clearly that we will take action against those. We will interdict their operations, we will disrupt their supply lines, we will disrupt these attacks," Hadley said.

Sen. John McCain, R-Ariz., speaking in a separate interview, agreed with the administration's approach. "Everybody knows the Iranians are playing in Iraq and they are trying to drive us out of Iraq so they can assert their age-old ambitions for influence in the Middle East. Everybody knows that. If there's Iranians in Iraq who are doing bad things, go after them, and let's get them."

Hadley said jihadists are also moving from Syria into Iraq, but he did not suggest that U.S. forces would move across the Iraqi border to pursue Iranians helping insurgents.

The priority "is what's going on inside Iraq. ... That's where we're going to deal with his problem," he said, adding, "Anytime you have questions about crossing international borders there are legal issues. ... We intend to deal with it by interdicting and disrupting activities in Iraq," Hadley said.

The vice president said Bush's decision to go against an Iraq Study Group recommendation to engage Iran and Syria in trying to find a political solution in Iraq is the right one, especially in light of Iran's role in providing improvised explosive devices to insurgents in Iraq, efforts to undermine the Iraqi government there and threats toward other regional neighbors.

"If you go and talk with the Gulf states or if you talk with the Saudis or if you talk about the Israelis or the Jordanians, the entire region is worried, partly because of the conduct of Mr. Ahmadinejad, the president of Iran, who appears to be a radical, a man who believes in an apocalyptic vision of the future and who thinks it's imminent," Cheney said.

"The presence of U.S. military out there, not only in terms of what we're doing in Iraq but also with our carrier task forces, for example, is indicated as reassurance to our friends in the region that the United States is committed to their security and that we're a major presence there now and we expect to continue to be one in the future," he said.

Cheney added that Iran is a danger to the rest of the world because if it acquires nuclear weapons, it not only will try to fulfill the regime's vision of global Islamic rule but will have the ability to control oil transits in and out of the Straits of Hormuz, where over 20 percent of the world's supply of oil — more than 18 million barrels a day — passes daily.

Iran is also working with Syria to interfere with efforts to build peace in the Mideast region, supplying terror groups Hezbollah and Hamas militarily and financially.

Ahmadinejad Builds New Alliance

Iranian President Mahmoud Ahmadinejad is currently on a four-nation visit to Latin America, which led off with a meeting with anti-American Venezuelan President Hugo Chavez. The two announced that they are building a $1 billion investment fund to fight U.S. interests. That's on top of a $2 billion fund already in the works.

Ahmadinejad, who along with Chavez chanted, "Death to U.S. imperialism," said he is working toward the day when there is no more America. During his four-day trip, he was meeting with Ecuadorian President Rafael Correa, who wants to kick the U.S. military out of his country, Nicaraguan President and Sandinista leader Daniel Ortega and Bolivian President Evo Morales, a close ally of Chavez.

Rep. John Tierney, D-Mass., a member of the House Permanent Select Committee on Intelligence, said that Chavez's and Ahmadinejad's reaching out and making noise internationally is a "great mask for their troubles at home." But he criticized the Bush administration for not engaging Iran or Venezuela.

"Ahmadinejad certainly has all sorts of economic problems locally and our failure to engage these countries in a meaningful way allows them to try and focus their internal problems outside so they don't have to address the people at home with how bad, how failed their domestic policies are," Tierney told FOX News. "You can't ignore any of these countries ... the way the administration has."

FOX News' Eric Shawn and The Associated Press contributed to this report.