TOKYO – Japan's Okinawa on Friday approved the long-stalled relocation of a controversial US military base, the defence ministry said, a breakthrough that looks set to remove a decades-long source of friction between Tokyo and Washington.

Local bureaucrats signed a document that gives the governor's green light to a landfill, paving the way for the construction of a new base on the coast.

The defence ministry's Okinawa bureau confirmed that it had received the document, which bore the governor's seal, from local government officials.

"The office received the document at 10:50 am. It was approved," said a ministry official at the bureau.

After years of staunch opposition, Okinawa governor Hirokazu Nakaima this week met Prime Minister Shinzo Abe, who pledged a big cash injection into Okinawa's economy every year until 2021.

Nakaima's nod marks a breakthrough on an original 1996 agreement to shut the Futenma airbase, which is in a densely populated urban area.

The United States affirmed in 2006 it would re-site the base on the coast, but the move has been stymied by opposition throughout Okinawa, which feels overburdened by its outsized share of the American military presence in Japan.

The governor is expected to announce his decision on Friday afternoon on Okinawa, where local residents have already reacted furiously to the news.

In the meeting with the Okinawa chief on Wednesday, Abe pledged an unheralded cash bonanza for the archipelago, at least 300 billion yen ($2.9 billion) for Okinawa's economic stimulus budget every year until fiscal 2021.

The package of proposals also includes halting operations at Futenma within five years and the early return of the land.

Nakaima has been a bitter critic of the central government, which he says is unsympathetic to the southern tropical island, which hosts around half of all the 47,000 military personnel in Japan.

Winning his approval marks a significant achievement for Abe, and one that is expected to burnish his credentials in Washington after years of frustration over the issue.

Observers have pointed to the timing of the deal on the base move and Abe's controversial visit Thursday to the Yasukuni war shrine, seen as a symbol in northeast Asia of 20th century Japan's brutal imperialism.

The visit, the first by a sitting premier since 2006, drew sharp rebukes from South Korea and China, as well as rare criticism from Washington, which said it was "disappointed".

Critics say Abe may be counting on the base deal to remove some of the sting in Washington's reaction.

Abe, who did not visit the Yasukuni shrine during a previous stint as prime minister, returned to power in part by accusing a left-leaning government of jeopardising the US alliance through the feud over Futenma.