Koro Bessho, the Japanese ambassador to South Korea, also defended Tokyo's plan to increase its defense budget this year for the first time in 11 years amid an increasingly bitter territorial dispute with China.
Japan's newly elected, right-wing Prime Minister Shinzo Abe sent a special envoy to South Korean President-elect Park Geun-hye early this month, in a gesture to improve ties that were deteriorated under their predecessors.
"I obviously think that we are in a better position to talk about it after the new administration is introduced in Korea, because it is really important for the two leaders -- Madam Park Geun-hye and Prime Minister Shinzo Abe -- to try to iron out our relationship," Bessho told a forum in Seoul.
"So, I am optimistic that we can try to look for a relationship with a stable future," the Japanese ambassador said.
Relations between South Korea and Japan have been strained since outgoing President Lee Myung-bak made a visit -- a first by a South Korean president -- to the islets of Dokdo last August. Japan strongly protested the move, and renewed its claim to the East Sea islets.
Dokdo, which lies closer to South Korea in the body of water between the Korean Peninsula and Japan, has long been an issue of contention between the two countries. South Korea keeps a small police detachment on the islets, effectively controlling them.
Abe had also campaigned for revising the 1993 apology by Japan's then-chief Cabinet secretary Yohei Kono that acknowledged the Japanese military's role in capturing and forcing tens of thousands of Asian women into sexual slavery for Japanese soldiers.
Despite the nationalistic remarks by Abe, the Japanese ambassador insisted that the new Japanese prime minister
"shares" the same feelings of deep remorse as his predecessors and agrees with their heartfelt apology.
Asked about how Japan's new government will make specific efforts to mend ties with South Korea, Bessho replied: "I can say that Japanese prime ministers have acknowledged that, during the past, Japan has caused tremendous damages and sufferings, especially in Asia, and the government of Japan is squarely facing historical facts and expresses feelings of deep remorse."
"And that is something that Prime Minister Abe has shared," he said.
South Korean officials have warned Japan against shifting to the right, saying Seoul will maintain its vigilance on any attempts by Tokyo to act more confrontationally in territorial and other issues.
Abe's new government unveiled a US$226.5 billion stimulus package last week that called for the country's first increase in military spending in 11 years, an act Bessho downplayed during the forum.
"We have been spending 1 percent or a little lower of our GDP for defense expenditure. That is a remarkably low figure for a growing economy," the Japanese ambassador said.
"It's perhaps an increase, but it's talking about increasing from last year after 10 years of reduction," he said.
"So, even after a possible increase, I can see that is much less than what it was 10 years ago," Bessho said.
While sounding notes of optimism about future relations between Seoul and Tokyo, Bessho sidestepped the issue of Dokdo when asked about it.
"First of all, as I have said, our bilateral relations are so precious for both countries and for the region," the ambassador said, without mentioning the name of the islets.
"I think this is very important. We don't want the total relationship to be destroyed because of sensitive issues we have," he said.
President-elect Park has said the launching of new governments in South Korea and Japan will mark a "good starting point" in bilateral ties, but analysts said she will take a firm response if Abe provokes South Korea again over territorial and history-related issues.