Russia has likely given technology assistance to North Korea and Iran in return for their arms transfers to Moscow, a senior Pentagon official said Tuesday, casting it as an apparent move to expand security threats to the United States and others.

Deputy Assistant Secretary of Defense for Space and Missile Defense John Hill made the remarks in response to a senator's question over how Washington is handling emerging space security cooperation between Tehran and Moscow as he attended a Senate subcommittee session.

"It does not stop at Iran," he said during the session of the subcommittee on strategic forces under the Senate Armed Services Committee.

"It also involves North Korea as we've seen with Iran and North Korea providing Russia with missiles to support Russia's operations in Ukraine, and then Russia likely providing them with technology assistance in their programs to expand the threats that they present to us and to others," he added.

He did not elaborate on what technology aid Russia might have provided to Pyongyang.

Washington has suspected that the North has been seeking assistance from Moscow, including fighter aircraft, surface-to-air missiles, armored vehicles and ballistic missile production equipment, in exchange for its provision of ballistic missiles, munitions and other arms.

Hill stressed that the US has been keeping tabs on Russia's engagements with both Pyongyang and Tehran.

"We are certainly watching what they are doing," he said. "The ability to continue cutting off Russia and Iran and North Korea is fundamentally at the crux of it, but they are going to keep pressing on us."

Washington, Seoul and other countries have voiced concerns over the broad security implications of the burgeoning military cooperation between Russia and the North, which they believe could affect stability on the Korean Peninsula and beyond.

In a written statement, Hill noted Pyongyang's continued pursuit of its space program while portraying the recalcitrant regime as a "persistent threat."

"The DPRK continues to pursue its space program, conducting several reconnaissance satellite launch attempts over the last year in violation of multiple UN Security Council resolutions related to DPRK use of ballistic missile technology," he wrote. DPRK stands for the North's official name, the Democratic People's Republic of Korea.

"The DPRK also maintains previously demonstrated non-kinetic counterspace capabilities, including systems for jamming communications and GPS signals." (Yonhap)