Iran and North Korea are "evil twins" separated at birth who have joined forces in pursuit of nuclear programs that could have devastating consequences, a senior US lawmaker charged Wednesday.

Democratic Representative Greg Ackerman, who heads the Subcommittee on the Middle East and South Asia, a key panel of the House Foreign Affairs Committee, pulled no punches in his depiction of two rogue states seeking the bomb at all costs.

"It seems that the evil twins of Iran and North Korea have been separated at birth and have now reunited and found each other," Ackerman told the House Foreign Affairs Committee in a session assessing the impact of tightened sanctions on Iran.

"The combination of the two of them joining in their mutual interests is very lethal," he added.

"It seems to me that among terrorists and terrorizing nations, it almost seems that possessing a nuclear program is a right of passage to becoming a respected member of the international community and they (Iran) are pursuing that at all costs."

The rhetorical language used to link the countries was some of the most colorful since president George W. Bush grouped North Korea, Iran and Iraq in an "axis of evil" nearly 10 years ago.

Several lawmakers at the hearing expressed concern over reports that North Korea is providing ballistic missile technology and material to Tehran.

Ackerman noted that sanctions imposed on North Korea have devastated that nation, and how a similar outcome in the Islamic republic could spell disaster.

"I think we should reflect a bit on what happens when the Iranians are driven to that economic low point," and whether such "strangling sanctions" would ever produce the US goal of stopping Iran from acquiring a bomb.

"At what point do we make the determination that the sanctions, no matter how successful in measurable aspects, are not going to prevent the Iranians (from) running the clock on us until they have the weapon?"