United States President Barack Obama's administration is looking for ways to build up "moderate elements" within the Lebanese Hezbollah guerrilla movement and to diminish the influence of hard-liners, a top White House official said on Tuesday.

John Brennan, assistant to the president for homeland security and counterterrorism, met with Lebanese leaders during a recent visit.

"Hezbollah is a very interesting organization," Brennan told a Washington conference, citing its evolution from "purely a terrorist organization" to a militia to an organization that now has members within the parliament and the cabinet.

"There is certainly the elements of Hezbollah that are truly a concern to us what they're doing. And what we need to do is to find ways to diminish their influence within the organization and to try to build up the more moderate elements," Brennan said.

He did not spell out how Washington hoped to promote "moderate elements" given that the organization is branded a "foreign terrorist organization" by the United States.

"We don't deal with them," he acknowledged. Last month, the United States and Israel accused Syria of arming Hezbollah with increasingly powerful missiles and weapons technology. Brennan said he raised those concerns during his recent visit to the region.