TM Toyota Motor Corporation

TOKYO—With Japan's longtime security ties to the U.S. called into question in the presidential campaign, Prime Minister Shinzo Abe on Tuesday offered a stout defense of the alliance's role in protecting the globe and warned against "naked nationalism."

Mr. Abe also told The Wall Street Journal in an hourlong interview that the U.S. and other wealthy nations should uphold existing trade deals, and said he wanted to push through a Pacific trade agreement that presidential candidates of both parties have called a bad deal for America.

Asked whether U.S. troops could pull out of Japan and leave the nation to defend itself—a possibility raised by Republican front-runner Donald Trump —Mr. Abe was unequivocal.

"I cannot conceive of any situation within the foreseeable future when the U.S. presence wouldn't be necessary," he said.

Pointing to laws passed last year by Tokyo that make it easier for Japan to fight alongside the U.S. outside its territory, Mr. Abe said: "By strengthening the Japan-U.S. alliance, we'll strengthen deterrence and that will contribute to peace and stability in the region, not just Japan."

Japan and other Asian nations have drawn unusual attention in this year's campaign, as Mr. Trump has questioned the decades-old bedrock of U.S. military policy in the region. Republican candidates and Democrats Hillary Clinton and Bernie Sanders have criticized the Trans-Pacific Partnership trade agreement, which was reached last fall but hasn't been approved by Congress.

On the TPP, Mr. Abe said: "This is the birth of an economic zone that has 40% of the world's [gross domestic product], one that is protected by free and fair rules. Through it, the U.S., Japan and the other countries participating in TPP will achieve great profit and gain chances for growth."

He declined to discuss individual candidates directly but alluded several times to the views of Mr. Trump, who has said the U.S. needs to put its interests first. The Republican front-runner has questioned the benefit of U.S. alliances, including the North Atlantic Treaty Organization, for average Americans, saying recently that allies are "ripping off the United States. And you know what we do? Nothing." On Japan, Mr. Trump has said, "We have to let them take care of themselves."

The U.S. maintains about 50,000 troops in Japan, a presence that dates to the early post-World War II era and Cold War tensions with the Soviet Union. Today, China's growing military might is an important target of U.S. deterrence. Mr. Abe reiterated calls for Beijing to stop building artificial islands on what it calls Chinese territory in the South China Sea, where several nations have overlapping maritime claims.

In late May, Japan will host a summit of the Group of Seven industrialized nations, and Mr. Abe said it would be a forum to show leadership against actions displaying "naked nationalism." He said nations could address economic unease by boosting investment in infrastructure.

While U.S. politicians try to address the anger of American voters over stagnant wages and what candidates have described as an economy tilted in favor of powerful interests, the 61-year-old Mr. Abe is facing similar pressures at home. The leader of the conservative, pro-business Liberal Democratic Party, he took office in December 2012 promising that his pro-growth "Abenomics" policies would haul Japan out of a two-decadelong funk and stimulate strong growth.

But the economy has shrunk in two of the past three quarters and posted just 0.5% real growth in 2015. Real wages have declined for four years in a row, and the Bank of Japan's introduction of negative interest rates earlier this year has failed to help.

On Tuesday, the yen strengthened to its highest level against the dollar since October 2014, driving down the Nikkei Stock Average 2.4%. Until recently, a weak yen—which has helped produce record corporate profits—was seen as one of the few concrete achievements of Abenomics.

What's more, the leading gauge of inflation has hovered around zero recently, suggesting Mr. Abe is still far from achieving his promise to rescue Japan from more than a decade of deflation.

Mr. Abe defended his economic program and said it was on the road to success. He cited a strong job market and wage increases this spring by smaller companies, although he acknowledged that bellwether Toyota Motor Corp. was dialing back base-wage increases.

The prime minister said other countries were responsible for Japan's recent sluggishness and referred to the Federal Reserve's decision to start lifting interest rates.

"Japanese markets have fluctuated significantly as world markets have moved based on fears about an economic slowdown in China, a fall in oil prices and the trend in U.S. interest rates, but Japanese economic fundamentals are still solid," he said.

Still, economists widely expect further easing by the Bank of Japan and stimulus from Mr. Abe's government this year. He hinted that the G-7 summit would be an occasion for him to propose new government spending in Japan and urge other developed nations to do the same.

"In developed countries, I think there is a need to update old infrastructure, as well as investment in infrastructure that takes the environment into account," he said.

Write to Peter Landers at peter.landers@wsj.com

(END) Dow Jones Newswires

April 05, 2016 14:55 ET (18:55 GMT)

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