The United States ambassador to Iraq Ryan Crocker denies reports that American forces are operating across the Iraqi border into Iran.

"I can tell you flatly that US forces are not operating across the Iraqi border into Iran in the south or anywhere else," Crocker said in an appearance on CNN's Late Edition.

Ryan Crocker's remarks contradict an article published earlier in The New Yorker on a major escalation of US covert operations in Iran.

A report in The New Yorker published Sunday detailed what the author described as a major escalation of US covert operations in Iran.

Crocker acknowledged he had not read the report, but he denied one accusation in the article that US forces are crossing the Iraq-Iran border.

The widely quoted article in the magazine centers on a highly classified Presidential Finding on US Covert Actions to destabilize Iran.

The article said that US Special Operations Forces had been conducting cross-border operations from southern and southeastern Iraq for over a year.

Ryan Crocker also said the door was open to further discussions with Iran on the situation in Iraq.

"We keep the channel open here in Baghdad. We think it's important to have that option. But also, it's important to have talks for a purpose, not just for the sake of having another session. So we'll need to choose the timing when we think it will improve the situation, actually make some progress," Crocker added.

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