Secretary of State Antony Blinken said Thursday that the U.S. has "real concerns" about the growing military relationship between Russia and North Korea. 

Blinken, speaking in South Korea, said, "In terms of the support that Russia may be providing to the DPRK [Democratic People’s Republic of Korea], this is something that we are watching very, very closely. Very, very carefully.

"And of course, we have real concerns about any support for North Korea's ballistic missile programs, for its nuclear technology, for its space launch capacity," he added. 

North Korea has been supplying artillery shells and other munitions to Russia in recent months to fuel its war efforts in Ukraine, U.S. and South Korean officials have said, according to The Associated Press. And they suspect that North Korean leader Kim Jong Un could be seeking Russian technologies and other assistance in return to upgrade his own military. 

NORTH KOREA SPY SATELLITE PROGRAM RECEIVING TECHNICAL ASSISTANCE FROM RUSSIA, SOUTH KOREA WARNS 

"We’re seeing a two-way street. We’re seeing the DPRK provide military equipment to Russia for its brutal aggression against Ukraine, but we’re also seeing Russia provide technological support to the DPRK for its own military programs, and that’s a real concern for the security of Korea," Blinken also said. 

At a news conference with South Korean Foreign Minister Park Jin, Blinken said he and South Korea’s leadership discussed unspecified further actions the countries could take to intensify pressure on Moscow not to transfer military technology to North Korea in violation of multiple U.N. Security Council resolutions. 

NORTH KOREA BELIEVED TO BE SUPPLYING RUSSIA WITH MISSILES FOR UKRAINE OFFENSIVE, SOUTH KOREA SAYS 

South Korean intelligence also indicates Russia has been assisting North Korea in the construction and launch of its latest spy satellite.

The South Korean Unification Ministry addressed the suspected collaboration on Monday, stating that North Korea is likely to move forward with the launch in the coming months. 

"It is hard to predict when North Korea will make the third attempt for the launch. But there seem to be signs of the North receiving technical assistance from Russia," South Korean Unification Minister Kim Yung-ho said, according to Yonhap News Agency. 

Fox News’ Chris Pandolfo, Timothy H.J. Nerozzi and The Associated Press contributed to this report.