A man watches a TV screen at a train station in Seoul, showing a news program reporting about North Korea's missile program with file footage of North Korean leader Kim Jong-un, March 11. AP-Yonhap

The United States imposed sanctions on five Russian entities, including two Russian nationals, Friday, for aiding North Korea's ballistic missile programs.

"The DPRK continues to launch ballistic missiles in blatant violation of international law, posing a grave threat to global security," Brian Nelson, undersecretary of the treasury for terrorism and financial intelligence, was quoted as saying, referring to North Korea by its official name, the Democratic People's Republic of Korea.

"Today's actions respond to this threat by targeting a network of Russia-based individuals and entities complicit in helping the DPRK procure components for its unlawful ballistic missile systems," he added, according to the Treasury Department.

The department said the two Russian individuals and three Russian companies have been helping Park Kwang-hun, a North Korean representative based in Vladivostok who was designated by both the U.S. and the United Nations in 2018 as procuring supplies for the North's illicit weapons programs.

"As a result of today's action, all property and interests in property of the individuals and entities that are in the United States or in the possession or control of U.S. persons must be blocked and reported to OFAC (office of foreign assets control)," the department noted in a press release.

The move comes one day after the U.S. said the North had tested a new intercontinental ballistic missile (ICBM) system in its recent missile launches, conducted Feb. 27 and last Saturday (KST).

A senior administration official here also said the North may be preparing to stage a "full range" ICBM test.

North Korea has maintained a self-imposed moratorium on nuclear weapons and ICBM testing since November 2017, but said in January that it may consider "restarting all temporarily-suspended activities."

Sources in South Korea earlier said the North appeared to be repairing a nuclear test site that it purportedly demolished in 2018 to show its willingness to denuclearize amid leader Kim Jong-un's dialogue with then U.S. President Donald Trump. (Yonhap)