According to a report by Fox, Pentagon officials say Iran recently tried to launch a cruise missile from a small submarine designed by North Korea and has repeatedly tested liquid-fueled intermediate range missiles of a North Korean design. The launch was conducted by a "midget" submarine in the Strait of Hormuz on Tuesday and was pronounced a failure by USA officials.
In 2010 a Yono-class submarine sank a South Korean warship, killing all 40 crew on board.
But unnamed Pentagon officials say there is another collaborator with North Korea that appears to be helping it survive: Iran.
The new activity comes after the February test launch of a Pukguksong-2, which is the land-based version of the Pukguksong-1 SLBM and two tests of the KN-17 medium-range ballistic missile (MRBM) on April 5 and 16, 38 North said.
"In the past, we would see things in North Korea and they would show up in Iran".
"The very first missiles we saw in Iran were simply copies of North Korean missiles", said Jeffrey Lewis, a missile proliferation expert at the Middlebury Institute of International Studies at Monterey, per Fox News.
North Korea's Taepodong missile looks nearly identical to Iran's Shahab, according to defense analysts.
Images from an earlier week in April show Pyongyang has placed a second test barge for SLBMs, at Nampo Naval Shipyard on North Korea's western coast.
Satellite images reveal that the new infrastructure on North Korea's artificial islands might be a chunk of the country's expanding armed forces and the infrastructure could be utilized to launch nuclear missiles. Midget subs are used in shallow waters, where they can hide. North Korea has denied responsibility for the attack.
A USA defense official who declined to be identified stated, "When those midget subs are operating underwater, they are running on battery power-making themselves very quiet and hard to detect".
Together, North Korea and Iran may be developing a decisive advantage in land-based short- and medium-range missiles over the United States, which is restricted from developing such weapons by the 1987 Intermediate Range Nuclear Forces treaty with Russian Federation.
"We are being taken to the cleaners by countries that are not signatories to the INF", said Harris.
The test stand was used during 2014-2016 for launch systems verification, and pop-up and prototype testing of the Pukguksong-1 (KN-11) submarine-launched ballistic missile (SLBM), it said. Iran and North Korea are under no such constraints. North Korea has successfully carried out such a launch, and American defense officials believe that Iran is close to developing that capability.
A number of Iranian missiles have designs that appear to be based on North Korean designs, including a ballistic missile tested by Iran in January of this year.