Cuba said its foreign minister met with his North Korean counterpart in Havana on Wednesday and both rejected the United States' "unilateral and arbitrary" demands while expressing concern about escalating tensions on the Korean peninsula.
North Korea is searching for support amid unprecedented pressure from the United States and the international community to cease its nuclear weapons and missile programs.
The country, which has made no secret of its plans to develop a missile capable of hitting the U.S. mainland, has maintained warm political relations with the island just 90 miles (145 km) south since 1960, despite Cuba's opposition to nuclear weapons.
Some diplomats said Cuba was also one of the few countries that might be able to convince North Korea to move away from the current showdown with the United States that threatens war.
The ministers called for "respect for people’s sovereignty" and "the peaceful settlement of disputes," according to a statement released by the Cuban foreign ministry.
"They strongly rejected the unilateral and arbitrary lists and designations established by the U.S. government which serve as a basis for the implementation of coercive measures which are contrary to international law," the statement said.
U.S. President Donald Trump has also increased pressure on Cuba since taking office, rolling back a fragile detente begun by predecessor Barack Obama and returning to the hostile rhetoric of the Cold War.
The U.S. State Department was not immediately available for comment.
"On the situation on the Korean Peninsula, they expressed concern about the escalation of tensions," the statement read.
"The ministers discussed the respective efforts carried out in the construction of socialism according to the realities inherent to their respective countries."
The two Communist-run countries are the last in the world to maintain Soviet-style command economies, though under President Raul Castro, the Caribbean nation has taken some small steps toward the more market-oriented communism of China and Vietnam.
Cuba maintains an embassy in North Korea, but publicly trades almost exclusively with the South. Last year, trade with the latter was $67 million and with the North just $9 million, according to the Cuban government.