US President Barack Obama has pledged with Japan to take a firm line on a defiant North Korea but his administration also tried to calm rising tensions between Tokyo's new leader and China.
Obama promised to work closely with Japanese Prime Minister Shinzo Abe, who came to Washington in hopes of sending a strong signal of unity two months after his conservative Liberal Democratic Party swept back to power.
"You can rest assured that you will have a strong partner in the United States throughout your tenure,'' Obama told Abe in the Oval Office, calling the alliance with Japan, "the central foundation'' for US policy in Asia.
Obama said the two leaders discussed "our concerns about the provocative actions that have been taken by North Korea and our determination to take strong actions in response.''
North Korea on February 12 carried out its third nuclear test, ignoring warnings even from its ally China. Recently released satellite images have indicated that North Korea has again resumed activity at the testing site.
Abe, who first rose to political prominence as an advocate for a tough line on North Korea, said he agreed with Obama's position of not offering "rewards'' to Pyongyang and on the need for a new UN Security Council resolution.
But the White House appeared to want to lower the temperature between Japan and China, which has increasingly sent vessels near Japanese-controlled islands known as the Senkaku in Japanese and Diaoyu in Chinese.
Obama did not mention the issue but Secretary of State John Kerry, in a separate meeting with Japan's Foreign Minister Fumio Kishida, said he wanted to "compliment Japan on the restraint it has shown.''
The meetings came hours after Beijing lashed out at Abe over a newspaper interview in which he charged that China would eventually hurt its investment climate through assertive actions in the region.
Abe said the US-Japan alliance was "a stabilising factor'' and _ in remarks he nudged his translator to read out _ added: "We have always been dealing with the Senkaku issue in a calm manner and we will continue to do so.''
Abe later spoke in stronger terms in an address at a think tank. While promising to seek calm, he insisted that the islands belonged to Japan.
"We simply cannot tolerate any challenge now and in the future. No nation should make any miscalculation or underestimate the firmness of our resolve,'' Abe said at the Center for Strategic and International Studies.
The exchange marked a different tone than one month ago, when then secretary of state Hillary Clinton warned China not to challenge Japan's control of the islands, triggering a rebuke from Beijing.
Clinton, who was speaking during Kishida's last visit, had also reiterated that that the United States considered the islands to be under Japan's de facto control and therefore protected under a US security treaty.
On the eve of Abe's visit, Obama's top Asia adviser Danny Russel said the United States wanted to focus on diplomacy between Japan and China to avoid the risk of miscalculations between the world's second and third largest economies.
"No one wants to allow tensions to fester or to escalate,'' Russel said.
Abe, who was also prime minister from 2006 to 2007, is known for his outspoken views on security and wartime history.
He has been more circumspect in his comments since returning to office, while at the same time seeking to boost Japan's military spending for the first time in more than a decade.
Obama called for further economic cooperation with Abe, who has pursued what the markets have dubbed "Abenomics,'' which includes setting an inflation target and a sharply expansionary monetary policy.
But the Obama administration held firm on a free trade pact known as the Trans-Pacific Partnership. The Liberal Democratic Party had said during the election that Japan would only enter talks if certain sectors are exempt.
Abe did not announce a decision on joining talks on the proposed deal. But the two governments issued a statement saying goods would be off the table, even if the outcome of an eventual deal could reach a different conclusion.