04/16/2008 05:12 am ET Updated May 25, 2011

Petraeus Ready To Talk To Iran Again

In an exclusive interview with "Nightline's" Terry Moran, the American Ambassador to Iraq said he was concerned about Iranian influence in Iraq.

When asked if Americans were in a "proxy war" with Iran, Ryan Crocker said, "It may be that the Iranians see it in that light, we certainly do not."

But he also added that "we don't want to have just what you describe as a proxy war with Iran inside Iraq, and that is why we are willing to sit down with Iran face to face for talks on Iraqi security at the invitation of the Iraqi government. We've had three rounds of those talks and we've told them we are ready to again."

Watch the exclusive interview tonight on "Nightline" at 11:35 pm.

Both Ambassador Crocker and the top commander in Iraq, General David Petraeus stressed the importance of Arab involvement in Iraq and said American troops might be in Iraq for the long haul.

"We will need to be there for a while," Petraeus said, adding that "over time, the role of our forces and our presence will change."

Crocker described American involvement in Iraq as a "multi-year project."

In Senate testimony today, General Petraeus recommended suspending troop withdrawals after July, telling members of Congress that while progress in Iraq is "real," it was also "fragile and reversible."

But Petraeus told ABC news he was upbeat about gains Iraqis have made, citing rising oil revenues and participation in the global market as signs of improvement and steps toward self-government.

Read more on ABC News Nightline