WASHINGTON - The United States has halted nearly $160 million in U.S. aid to Burkina Faso after determining the January ouster of President Roch Kabore constituted a military coup, triggering aid restrictions under U.S. law, a State Department spokesperson told Reuters on Friday.

The State Department made the determination, which had not been previously reported, after "careful review," a department spokesperson said. The decision was made in line with a U.S. law under which U.S. foreign aid - except funds to promote democracy - must be stopped to a country whose elected head of government is deposed by military coup or in a coup in which the military plays a decisive role.

"The State Department assesses that a military coup took place in Burkina Faso," a spokesperson for the department said in an email. "Therefore, approximately $158.6 million in foreign assistance that benefits the Government of Burkina Faso is restricted," it said.

In a notice to Congress, a copy of which was seen by Reuters, the State Department said it was exploring the possibility of overcoming the aid restrictions when in the U.S. national interest, notably to provide lifesaving assistance in the health sector.

The State Department said on Jan. 31 that it had paused most assistance to Burkina Faso after the country's military leader Paul-Henri Damiba led a junta that on Jan. 24 overthrew Kabore.

But Washington had not formally determined that the events in the West African country amounted to a coup and had not made a final decision on the fate of the aid.

Separately, Millennium Challenge Corporation, a U.S. government foreign assistance agency, said on its website that on Jan. 31 it had paused activity related to a compact agreement signed in August 2020 for $450 million in funding to Burkina Faso. Such an agreement typically covers a five-year period.

The MCC did not immediately respond to an email on Friday asking if that assistance was now halted.

Damiba was sworn in as president this week. He had cited Kabore's inability to curb an Islamist insurgency that has killed thousands of people and forced more than one million people to flee their homes in the West African country.

The military coup in Burkina Faso followed takeovers in Mali, Guinea and Chad since 2020, raising fears of coup contagion among regional leaders.

It has also weakened France's West Africa alliances, given three of the coups - in Mali, Chad and Burkina Faso - have taken place in ex-French colonies. The military takeovers have also emboldened jihadists who control large swathes of territory and opened the door for Russia to fill the vacuum.

(Reporting by Arshad Mohammed in Saint Paul, Minn. and Humeyra Pamuk in Washington; Editing by Michelle Nichols, Howard Goller and Rosalba O'Brien) ((arshad.mohammed@thomsonreuters.com))