Japan's next leader Yukio Hatoyama was to meet the U.S. ambassador on Thursday as concerns simmered about the allies' ties after an election win by Hatoyama's party, which has pledged a more independent diplomatic course, Reuters reported. Hatoyama, whose Democratic Party of Japan (DPJ) crushed the long-ruling Liberal Democrats in Sunday's election, sought to reassure U.S. President Barack Obama in a phone call early on Thursday that the relationship would stay central to Tokyo's diplomacy. "I told him we think the U.S.-Japan alliance is the foundation (of Japanese diplomacy) and I would like to build U.S.-Japan relations with eyes on the future," Hatoyama told reporters after his conversation with Obama. The prospect of a Democratic Party administration in Japan, ruled for most of the past half-century by a conservative party that put the U.S. partnership at the core of its security stance, has raised worries in Washington about a tilt away from the alliance. Most analysts say no huge shift is in store once Hatoyama takes up the premiership on Sept. 16 but investors are also concerned about a possible rocky road ahead. The Democrats pledged in their campaign platform to create a more equal partnership with Washington while forging warmer ties with Asian neighbours such as China. -- SPA