WASHINGTON (Reuters) -- Iran and North Korea are working together to develop ballistic missiles and have made significant progress, the head of the Pentagon's Missile Defense Agency has said.
"It really is an international effort going on out there to develop ballistic missile capability between these countries," Army Lieutenant General Patrick O'Reilly told a forum on Capitol Hill.
Iran and North Korea each is at odds with much of the international community over their nuclear programs, and North Korea has tested an atomic bomb. Each has demonstrated a capability to launch missiles with more than one stage, critical to more advanced systems.
They are sharing know-how on avionics, propulsion, and materials, among other things, O'Reilly said.
"We've seen it for years and it continues," he said of such cooperation between North Korea and Iran, whose Shahab missiles are widely reported to be based on North Korean designs.
Their ability to fire missiles with a stable ignition and launch a second stage represents "a significant step forward" for both of them, O'Reilly said.
Asked which country was further ahead in missile development, he said it could be described as a "horse race" with no clear leader.
Other experts said Iran had demonstrated greater expertise with test-firing of a solid-fuel rocket with a stated range of some 1,900 kilometers -- enough to reach Israel, U.S. bases in the Gulf, or Southeastern Europe.
Solid-propellant missiles offer many advantages over those with liquid fuel. They are easier to store, harder to detect, and may be launched without a fueling process readily observable by spy satellites.
Iran's use of solid-fuel missiles demonstrated "a quantum leap in capabilities" over those shown by North Korea, Uzi Rubin, the former head of Israel's Missile Defense Organization, told Reuters in an interview.
"Basically, this is big-power league," he said, adding that the jury was still out, as far he was concerned, on whether the two had integrated their ballistic missile programs.
The U.S. Air Force's National Air and Space Intelligence Center, says Iran, with support from outside sources, within six years could produce a missile capable of hitting the United States.
"Iran has ambitious ballistic missile and space launch development programs and, with sufficient foreign assistance, Iran could develop and test an ICBM capable of reaching the United States by 2015," it said in a new report.
The report, made available by the Federation of American Scientists, said North Korea was continuing work on its Taepodong 2 "that could reach the United States with a nuclear payload" if developed as an intercontinental ballistic missile.
The Obama administration has asked Congress for $7.8 billion for the U.S. Missile Defense Agency in fiscal 2010, down about $1.2 billion from 2009. Congress is considering adding more funds.