U.S. Forces Japan said Friday it has decided to extend COVID-19 restrictions on its personnel's activities outside bases in Japan by one week through the end of January.

The decision was made "due to the continuing increase of COVID-19 cases throughout Japan," fueled by the rapid spread of the highly contagious Omicron variant of the coronavirus, U.S. Forces Japan said in a press release.

The measures have been implemented since Jan. 10 following a surge in virus infections among American military personnel in prefectures such as Okinawa and Yamaguchi.

Clusters of COVID-19 cases at U.S. military facilities in prefectures hosting U.S. military bases have been reported since last month.

The spike in new cases prompted Japanese Foreign Minister Yoshimasa Hayashi to ask the U.S. side earlier in the month to impose curfews at U.S. military bases in Japan.

Under the measures, the movement of military personnel outside military facilities is restricted to essential activities, and wearing a mask is required even on bases.

The extension comes ahead of a virtual meeting later in the day between Japanese Prime Minister Fumio Kishida and U.S. President Joe Biden, the first formal summit between the two leaders since Kishida took office in October.

Hayashi told a parliament session that a total of 6,350 coronavirus cases had been confirmed among U.S. forces personnel stationed in Japan as of Wednesday, of which 4,141 were in the southern island prefecture of Okinawa.

Okinawa Gov. Denny Tamaki has demanded that restrictions on U.S. military personnel be maintained "until the virus spread is brought under control."

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