WASHINGTON (AFP) - Japan's new conservative Prime Minister Shinzo Abe on Thursday starts a visit to the United States (US) in which he hopes to show a firm, unified line to an assertive China and a defiant North Korea.

Mr Abe holds his first meeting on Friday with President Barack Obama at a time of growing tensions between Japan and China, which is seen as challenging Tokyo's control over strategic islands, and days after a nuclear test by Pyongyang.

Fresh from a convincing December election victory and with high approval ratings, Mr Abe has taken small steps toward a harder Japanese stance including moving to step up military spending by the officially pacifist state.

Mr Danny Russel, Mr Obama's top advisor on Asia, said that the United States wanted a diplomatic solution to ease tensions but also reiterated a veiled warning to China over contested islands in the East China Sea.

Mr Obama "remains supportive of the peaceful efforts to find diplomatic resolution to outstanding issues of territorial claims", Mr Russel told reporters on a conference call.

Mr Obama has also "been clear in the US opposition to coercive actions or unilateral steps that threaten the stability of the region", he said.

Mr Russel said that the United States wanted to avoid "miscalculation" between China and Japan, saying that the world's second and third largest economies were leading a region that is "the driver of growth and dynamism".

Mr Abe's visit comes one month after then secretary of state Hillary Clinton stepped up the tone, warning Beijing not to challenge Japan's control over the islands known as the Senkakus in Japanese and the Diaoyu in Chinese.

The remarks by Mrs Clinton, a forceful advocate for a greater US focus on Asia, triggered a reprimand from China but heartened Mr Abe's government which has counted on a united front with the United States.

In an interview with The Washington Post ahead of his trip, Mr Abe voiced hope that the US alliance - and the presence of 47,000 American troops on Japanese soil under a security treaty - would send a message to China.

"It is important for us to have them recognize that it is impossible to try to get their way by coercion or intimidation," Mr Abe said.

China contests Japan's historical claims in the area and voiced anger after Japan last year nationalized the islands, a move Mr Abe's predecessor said was meant to avert a more provocative proposal.

Officials said that the two leaders would also look to show a common front on North Korea, which carried out its third nuclear test on Feb 12 despite pressure from virtually all nations including its main ally China.

Mr Abe, who previously served as prime minister from 2006 to 2007, has throughout his career been known as a hawk on North Korea and has been hesitant over periodic attempts by Washington to reach out to the communist state.

Mr Abe's Liberal Democratic Party swept out of power the left-leaning Democratic Party of Japan, which initially had a rough relationship with Mr Obama by pushing for the withdrawal of more US troops from crowded Okinawa island.

Mr Robert Hathaway, director of the Asia program at the Woodrow Wilson International Center for Scholars, expected Mr Obama to be forthright in public comments but to talk privately to Abe about avoiding miscalculations that could send tensions soaring with China.

"This is less a visit about tangible deliverables, of which I expect there will be relatively few of prominence, and more about the symbolism of reinforcing the strength of the US-Japan alliance," he said.

Mr Abe, who faces upper house elections in July, is likely to speak to Mr Obama about whether Japan will join talks on the Trans-Pacific Partnership, a US-backed free trade pact bitterly opposed by many Japanese farmers.

White House official Michael Froman said that any nation that enters negotiations would be expected to put "everything on the table".

Mr Abe, during his campaign, said that certain sectors should be exempted.