Japan's new Prime Minister Shigeru Ishiba said Wednesday that missile attacks by Iran on Israel were "unacceptable", warning against an escalation into "full-on war".
Ishiba made the comments after a phone call with U.S. President Joe Biden, following his appointment as prime minister in parliament on Tuesday.
"Iran's attack is unacceptable. We condemn this strongly. But at the same time, we would like to cooperate (with the United States) to defuse the situation and prevent it from escalating into a full-on war," Ishiba told reporters.
Foreign Minister Takeshi Iwaya said: "Peace and stability in the Middle East are extremely important for Japan and we strongly urge all parties concerned to calm the situation."
Ishiba, a former defence minister, who visited Taiwan in August, backs the creation of a regional military alliance for mutual defence along the lines of NATO.
Ishiba said the Japan-U.S. defence alliance "strengthened significantly" under his predecessor Fumio Kishida.
Kishida worked to double defence spending and boost ties with the United States and other countries rattled by China's rise and the actions of Russia and North Korea.
"I would like to inherit that policy and strive to make it stronger," Ishiba said he had told Biden.
"I told him we would like to strengthen the network of like-minded countries as well," Ishiba added, mentioning South Korea, Australia, India and the Philippines.
The pair agreed to continue close cooperation on issues concerning China, North Korea's weapons programme and the Ukraine war, Japan's foreign ministry said.
They also discussed the fate of Japanese citizens kidnapped by North Korea in the 1970s and 80s.
The White House also issued a statement saying Biden had called Shigeru to congratulate him on becoming premier.
"The President said he looked forward to working closely with Prime Minister Ishiba to continue deepening the US-Japan global partnership," it said.
Chinese President Xi Jinping also congratulated Ishiba, Chinese state media reported on Wednesday.
Relations between the neighbours have worsened as China builds its military presence around disputed territories in the region, and as Japan boosts security ties with the United States and its allies.
But after Ishiba won a ruling party leadership vote last week, China said it wanted to improve ties with Japan.
The "long-term, sound and steady development" of relations "serves the fundamental interests of the two peoples", Beijing's foreign ministry spokesman Lin Jian said Friday.
