Guinea-Bissau's President Umaro Sissoco Embalo threatened to expel a political mission sent to his country by the Economic Community of West African States (ECOWAS), the political and economic bloc said on Sunday.

A dispute over when Embalo's presidential term, which began in 2020, should end has heightened tensions that risk unrest in a nation with a history of military coups.

The tiny West African nation's political opposition says Embalo's term should have expired last week, while the Supreme Court of Justice has ruled that it ends on September 4.

Embalo, who chaired ECOWAS from mid-2022 to mid-2023, said on February 23 that presidential and legislative elections would not be held until November 30.

ECOWAS said in a statement on Sunday it had deployed a mission from February 21 to 28 together with the United Nations Office for West Africa and the Sahel (UNOWAS) to help reach a consensus on how to conduct an election this year.

But it added: "The Mission departed Bissau in the early morning of 1st March, following threats by H.E. Umaro Sissoco Embalo to expel it."

On Wednesday, Embalo visited Moscow for talks with Russian President Vladimir Putin. Guinea-Bissau is a former Portuguese colony that gained independence in 1974.