Japanese Prime Minister Shinzo Abe has warned that military confrontation with Iran will impact global peace and stability, as he visits the Middle East hoping to ease tensions spiked by the US killing of a top Iranian general.

His comments came at the start of a five-day Gulf tour that had been thrown into doubt after Tehran responded to the attack on Qasem Soleimani by launching a barrage of missiles at bases hosting American troops in Iraq, prompting fears of all-out war.

But as those concerns receded, the Japanese premier decided to go ahead with the visit and on Sunday discussed regional tensions during an hour-long meeting with Saudi Crown Prince Mohammed bin Salman in northwestern Al-Ula province, according to foreign ministry spokesman Masato Ohtaka.

“Any military confrontation in the region that includes a country like Iran will have an impact not only on peace and stability in the region but the peace and stability of the whole world,” Abe said, according to Ohtaka.

Abe called “on all relevant countries to engage in diplomatic efforts to defuse tensions”, Ohtaka added.

The spokesman said the two leaders agreed on working closely on maritime security in the region and discussed Tokyo's decision to send a destroyer for intelligence activities along with two P-3C patrol aircraft to the Middle East.

Japan, however, will not join a US-led coalition in the region.

Tokyo has walked a fine line in balancing its key alliance with Washington and its longstanding relations and interests with Tehran.

Ohtaka said that Abe stressed the importance of a continuous and stable Saudi oil supply to Japan.

The prime minister's tour will also include visits to the United Arab Emirates and Oman.