Leaders of Japanese opposition parties on Monday expressed concern over the U.S. military attack on Venezuela and criticized the Japanese government's response, local media reported.

"I'm concerned that the attacks may significantly shake the international order," Tetsuo Saito, leader of Komeito, a former ally of the ruling Liberal Democratic Party, said at a party conference according to Jiji Press.

Saito added that the government should "urge the United States to understand the importance of abiding by international law."

Yoshihiko Noda, head of the main opposition Constitutional Democratic Party of Japan, told reporters that the U.S. attacks "are questionable in light of international law."

"Not only Japan but also middle-power states, including European and Asian countries, should cooperate and demand (legal compliance)," Noda said.

The remarks came a day after Japanese Prime Minister Sanae Takaichi posted on the social media platform X on Sunday that her government will work to help stabilize the situation in Venezuela, without commenting directly on the U.S. military action.

The United States launched a large-scale military operation in Venezuela, during which Venezuelan President Nicolas Maduro and his wife were "captured and flown out of the country," according to U.S. President Donald Trump's post on Truth Social on Saturday.

(With input from Xinhua)