North Korea on Saturday denounced U.S. pledges of battle tanks to Ukraine, claiming Washington was “further crossing the red line” to win hegemony by proxy war, state media KCNA reported.

North Korean leader Kim Jong Un’s powerful sister, Kim Yo Jong, made the remarks in a statement carried by KCNA, saying that North Korea will “stand in the same trench” as Russia against the United States.

The United States said this week it would supply Ukraine with 31 of its most advanced battle tanks after Germany made a similar announcement. This scrapped a taboo in Western support for Ukraine’s battle against Russia’s invasion by pledging arms that have a mainly offensive purpose.

“I express serious concern over the U.S. escalating the war situation by providing Ukraine with military hardware for ground offensive,” Kim Yo Jong said in the statement.

The United States and Western countries “have neither right nor justification to slander sovereign states’ exercise of the right to self-defence.”

Nuclear-armed North Korea launched an unprecedented number of missiles last year, including intercontinental ballistic missiles (ICBMs) capable of reaching the U.S. mainland. U.S. and South Korean officials have also warned the North could be preparing for its first test of a nuclear device since 2017.