Tokyo yesterday shrugged off heavy US pressure for speedy implementation of a deal to relocate one of the military bases on Okinawa island in a response certain to anger Washington and fuel worries about the loyalties of Japan's new ruling Democratic party.

The decade-old plan to move the Futenma Marine air base from the centre of a busy city to scenic Henoko Bay in northern Okinawa has become a lightning rod for friction since the DPJ's election victory in August over Japan's long-ruling and pro-US Liberal Democratic party.

Barack Obama, US president, has personally pushed for “expeditious” action to implement the move, which was agreed by previous US and Japanese administrations. But Yukio Hatoyama, Japan's prime minister, stressed the importance of considering public feelings in Okinawa, where the move is deeply unpopular, and said an immediate decision on the relocation plan would “lead nowhere”.

“We want to explore other sites than Henoko,” Mr Hatoyama said yesterday. “My understanding is that several months are likely to be needed.”

With key DPJ leaders, including the foreign and defence ministers, favouring the move, observers said Mr Hatoyama's decision reflected a determination to avoid upsetting the small Social Democratic party, a leftwing junior coalition partner that insists the base be shifted off Okinawa.

Mizuho Fukushima, SDP head, said she was “very glad” there had been no “hasty decision”.

However, the opposition LDP immediately seized on the postponement as a further sign of Mr Hatoyama's indecision and lack of leadership. The prime minister has insisted he will make the final call on the issue but has repeatedly wavered on when he would do so.