WASHINGTON (Kyodo) -- The Indo-Pacific region, where China's presence is rapidly growing, would be a more challenging "away game" for the United States without Japan and other allies, the U.S. ambassador to Tokyo said Friday, suggesting that this view must be upheld regardless of the outcome of next month's presidential election.

At a think tank event in Washington, Rahm Emanuel, who has been serving as the U.S. envoy to Japan since late 2021, said the two countries have been able to build a foundation for the next several decades under the administration of President Joe Biden.

Emanuel said the last three years should be seen as a period when the alliance was focused on "projecting into the future," with the relationship for the first time being free of any "sand in the gear," unlike in the past when tensions over trade or defense issues sometimes prevented them from going forward.

For the robust relationship to strengthen further, he underscored that public opinion and people-to-people exchanges are vitally important.

He also cautioned not to underestimate Japan's soft power, such as through popular professional baseball players in the United States and anime series.

"When you're trying to do politics and you're trying to move things, to have a partner that is extremely popular in your own country is a huge benefit," Emanuel said at the symposium, organized by the Center for Strategic and International Studies and the Japan Foundation.

"There's no better friend to have than Japan," he added, noting that the country has transformed into a global partner for the United States that is now capable of playing a more active role in the region and beyond.

While it remains unclear who will win the U.S. presidential election on Nov. 5, he said the multilateral partnerships involving the two countries and Seoul as well as other like-minded capitals in the region should be deepened.

"For the United States, the Indo-Pacific is an away game, and without allies, it's a really away game," he said, stressing the need to "work with alliances and allies" in the region.

Later in the symposium, U.S. Deputy Secretary of State Kurt Campbell, who visited Tokyo earlier this week for meetings with senior officials, said it is becoming crucial for the two countries to share more intelligence with each other.

With Emanuel's efforts "behind the scenes," Campbell said Japan has become, "in some ways, a Five Eyes-plus member and we want that to continue," referring to the decades-old intelligence-sharing alliance between Australia, Britain, Canada, New Zealand and the United States.

Campbell, a major architect of the U.S. administration's approach to Asia, also said that for whoever comes into power as the next president, it will be increasingly necessary to recognize that the growing alliance with Japan cannot be sustained only through cooperation on defense and regional security issues.

Because "technology is at the center of what we do and what we seek to do" on various fronts, he said an even more robust economic relationship is essential.