Algeria has closed its border with Mali, where an aerial assault by the French military is targeting armed Islamist groups occupying the north of the country, the foreign ministry said on Monday.
"I confirm" the closure of the border with Mali, ministry spokesman Amar Belani told AFP.
"We have informed the Malian side of the measures taken to close the border, which has already been secured since the recent events unfolded in Mali," he said.
Belani was speaking at the end of a visit by Mali's interim premier Diango Cissoko to Algeria, and three days after the French air strikes began.
"Algeria has always been motivated by the desire to help the neighbouring country to overcome the difficulties that it faces, in order to find a durable solution to the crisis and a peaceful management of the transition," Belani said.
"Since the start of the crisis in Mali, this solidarity has resulted in financial and humanitarian aid, and support for the Malian army in strengthening its ability to combat terrorism and organised crime."
On Saturday, the Algerian foreign ministry expressed its "unequivocal support" for the transitional authorities in Mali, where the army, supported by French troops, is seeking to counter an offensive by Islamists towards the government-held south.
Algeria, which shares a 2,000 kilometre (1,200 mile) desert border with Mali, has always favoured a political solution to the crisis in its southern neighbour, where Al-Qaeda-linked Islamists took control of the north after a coup in Bamako last year.
But French Foreign Minister Laurent Fabius on Sunday said Algeria had authorised the overflights of Rafale fighter jets based in France, adding that the Algerians would have to close their border when troops pushed into northern Mali.
"What we have in mind is that if African troops move into the north of the country, the Algerians will have to close their border," Fabius said.
Belani said that the Algerian Foreign Minister Mourad Medelci had spoken to Fabius on Monday evening about the situation in Mali.
The UN Security Council was to discuss the conflict later on Monday at the request of France, which is seeking a speedy implementation of Resolution 2085 that authorises the deployment of a 3,300 strong West African intervention force.
In December, Libya announced the closure of its borders with Algeria, Niger, Chad and Sudan because of the deteriorating security situation in the south of the country.