Okinawa Gov. Hirokazu Nakaima on Sunday expressed his "extreme regret" over the government's decision to relocate the U.S. Marine Corps' Futemma Air Station base within the southernmost prefecture, said reports from Naha, capital of Okinawa Prefecture.

Nakaima made the remarks during talks at the Okinawa prefectural office with visiting Prime Minister Yukio Hatoyama, who disclosed his government's plan to relocate the base within Okinawa.

The governor said that it will be "extremely difficult" to carry out the plan as Okinawa residents hope that the Futenma military facilities will be moved out of the prefecture.

Hatoyama visited Okinawa Sunday for the second time this month to settle the thorny issue concerning the relocation of the U.S. Futenma base.

During the meeting with Nakaima, which is open to the press, Hatoyama told the governor that the government needs to ask Okinawa locals to accept the relocation of the base to Henoko in Nago, Okinawa Prefecture.

A "heartbreaking" decision as it is, it serves to achieve the return of the land occupied by the U.S. base to Okinawans, said Hatoyama, who also conveyed his sincere apology for "causing so much confusion" to local residents.

On Saturday Japan and the United States broadly agreed on a fresh agreement to relocate the U.S. Futenma base to the coast of Henoko.

The pact, to be announced on May 28, was reached by Foreign Minister Katsuya Okada, U.S. Ambassador to Japan John Roos and foreign and defense officials of the two countries during a meeting Saturday.

Under the new plan, the two sides agreed not to delay the process of the environmental assessment conducted under the existing plan to reclaim land on the coast of the U.S. Marines' Camp Schwab in Henoko in Nago, and consider joint use of the relocation facility with Japan's Self-Defense Forces.

The central government is leaning towards a slight modification of the 2006 accord that would see a new airstrip built on an elevated platform in the shallow waters off the coast in Nago, Okinawa, to facilitate the heliport functions of the Futemma base, instead of one reclaimed land from the sea, as per the existing bilateral accord between the two countries.