THE PROVINCE of Sulu, composed of several islands in the southwestern end of the country, is closing its borders to travelers from the neighboring Malaysian state of Sabah, where cases of the new coronavirus variant have been reported.

Sulu Governor Abdusakur M. Tan, in a briefing on Tuesday, said travel to Sabah would also be banned.

“No one can go to Sabah and no one from Sabah can come here,” he said in Filipino.

Sulu and Sabah, which are separated by waters that are about 500 kilometers long, have close trading ties. Sulu depends on its Malaysian neighbor for rice.

Mr. Tan aired his concern about a potential rice shortage but said the lockdown would last “for as long as necessary.”

He said authorities in Sabah have implemented a border lockdown. Gillian M. Cortez