TOKYO: Japan's government on Tuesday delayed a decision on where to move a controversial US military air base, drawing out a festering three-month-long row with Washington.

The Kyodo News agency said the cabinet would not reach a decision on the issue until next year, while earlier media reports said thecoalition government may wait until May to make up its mind.

Japan and the United States, key allies for decades, are at loggerheads over where to relocate an airbase on the island of Okinawa that was due to be moved from a city area to a coastal region of the southern island by 2014.

Since coming to power in September, the centre-left government led by Prime Minister Yukio Hatoyama'sDemocratic Party of Japan (DPJ) has angered US officials by saying it would review the 2006 base relocation pact.

The scheduled relocation, agreed while previous conservative governments were in power in both countries, is part of a wider pact to review the 47,000-strong American troop presence in Japan.

Hatoyama has said the base could be moved off the island or even out of the country, as demanded by his left-leaning coalition partners and many Okinawans annoyed by aircraft noise and the large American troop presence.

A US-Japanese working group, after two meetings, has scheduled no further talks on the prickly issue for now, Foreign Minister Katsuya Okada has said.

Hatoyama's junior partners, the Social Democrats, have threatened to quit the coalition if the DPJ ends up agreeing to the original relocation plan.

US President Barack Obama has urged Japan to "expeditiously" implement the original plan of moving theFutenma Marine Corps base to the Henoko coastal region, where two new offshore runways would be built.

While Tokyo is weighing various options, it will earmark expenses related to the existing relocation plan in the fiscal 2010 budget, reports said.