

During their first meeting since Mr. Abe's party returned to power in December, the two leaders agreed to act resolutely against North Korea as it continues to develop its nuclear-weapons program. Mr. Abe called for additional sanctions against North Korea, as he pledged closer cooperation with the U.S. and South Korea, a neighbor with which Japan has had frosty relations despite their close economic ties.

Mr. Abe said he and Mr. Obama agreed that the security alliance between Japan and the U.S. is improving after a period of occasional bumps during the prior three years when his long-ruling conservative party was in Japan's opposition.

Prime Minister Shinzo Abe speaks at a news conference on Friday in Washington D.C., where he met with President Barack Obama. Getty Images

"The U.S.-Japan alliance is the central foundation for our regional security and so much of what we do in the Pacific region," Mr. Obama said after a bilateral meeting with Mr. Abe at the White House.

Mr. Abe said he discussed recent tension between Japan and China over a group of uninhabited East China Sea islands, an issue that has concerned U.S. officials.

"I told Mr. Obama that Japan intended to respond always calmly and that's exactly what we have done up until now," Mr. Abe said. "We agreed the existence of the Japan-U.S. alliance does contribute to the stability of the region."

Japan and the U.S. also issued a joint statement saying the countries are continuing to discuss Japan's participation in negotiations over a regional free-trade pact known as the Trans-Pacific Partnership. "The two governments will continue their bilateral consultations with respect to Japan's possible interest in joining," the statement said. "While progress has been made on these consultations, more work needs to be done."

At a news conference, Mr. Abe said he hoped to decide quickly whether Japan would formally join the Trans-Pacific trade talks. He said he confirmed with Mr. Obama that Japan needn't promise in advance to give up tariffs on some agricultural products with "sensitivities" at home.

Separately, Mr. Abe said he hoped to pick a new governor of the Bank of Japan quickly on his return to Tokyo.

To help ease the steep costs of energy imports following Japan's nuclear accident in 2011, Mr. Abe told Mr. Obama that he would like the U.S. to allow exports of natural gas to Japan, a Japanese official said. Washington currently limits exports abroad other than to its free-trade agreement partners.

Mr. Abe said that since he took power in December, he has promised an increase in Japan's defense budget for the first time in more than a decade and allowed a boost in the size of Japan's military personnel. He also said Japan intends to ease its domestic laws that severely limit the operational scope of its military so the nation can play a bigger role in the security alliance to ensure regional stability.

Such a change would allow Tokyo to shoot down a missile flying to the U.S. from North Korea, or allow Japanese troops to fire at enemy forces if friendly troops came under fire during peacekeeping operations. Mr. Abe also promised to host a second unit of X-band radar to boost ballistic missile defense in East Asia.

Mr. Abe's Liberal Democratic Power swung back to power in December elections, pledging a more assertive foreign policy and a stronger military. Such comments made Japan's Asian neighbors, particularly China and South Korea, nervous.

During his whirlwind visit to Washington, Mr. Abe's displayed his enthusiasm for a stronger Japan. As he greeted reporters on his plane to Washington, he wore an aviator's jacket labeled "Japan Air Self-Defense Force." On Friday morning, the prime minister ventured in freezing temperatures to lay a wreath at the Tomb of the Unknown Soldier in Arlington National Cemetery.

After a meeting and a working lunch with Mr. Obama, Mr. Abe headed to a Washington think tank, the Center for Strategic and International Studies, to deliver a speech in English titled "Japan is Back."

He reviewed his "Abenomics" policy, which has set off a strong rally in Japan's long-dormant stock market. He called again on the central bank to ease monetary policy and said his program of stimulus spending would lift economic growth by two percentage points and create 600,000 jobs.

"I make a pledge. I will bring back a strong Japan," Mr. Abe said.

Mr. Obama didn't make specific comments about Mr. Abe's economic policies, the Japanese official said. Some European officials have criticized Tokyo's monetary easing and the sharp drop in the yen's value that has resulted.

—Peter Landers contributed to this article.

Write to Yuka Hayashi at yuka.hayashi@wsj.com