PYONGYANG - The Democratic People's Republic of Korea (DPRK) vowed to take self-defense countermeasures against Washington's "hostile policy," official news agency KCNA said Friday.

"As long as the U.S. persists in its hostile policy toward the DPRK, according to its high-handed, arbitrary and gangster-like double standards, Pyongyang will push ahead with the countermeasures for self-defense, as it had already declared," a spokesman with the National Defense Commission (NDC) said in a statement.

The NDC also called on Washington to roll back its "hostile" policy and lift all sanctions, accusing the United States of employing double standards when responding to missile tests by South Korea.

On March 23, South Korea successfully test-fired a ballistic missile capable of reaching all parts of the DPRK. Three days later, the DPRK test-fired two ballistic missiles into the sea off its east coast.

If the ballistic missile launched by South Korea "is not problematic, our launch of satellites or rockets will be of no problem, either," the NDC said.

Possible "countermeasures" by Pyongyang include long-range missile launches or even a "new form" of nuclear test. The DPRK conducted nuclear tests in 2006, 2009 and 2013, drawing international condemnation and UN sanctions.