US Secretary of State Hillary Clinton arrived Monday in Algeria to discuss with President Abdelaziz Bouteflika the crisis in neighbouring Mali, large swathes of which have been overrun by Islamists.
Washington has launched a diplomatic offensive to secure Algeria's vital backing for a military intervention in Mali, where Al-Qaeda in the Islamic Maghreb (AQIM) is among militant groups tightening their grip on the north.
"Algeria being the strongest Sahel state became a critical partner in dealing with AQIM," a State Department official said aboard Clinton's plane, which touched down in Algiers shortly before 0530 GMT.
"In the context of what happened in North Mali when the government forces up there collapsed and the coup happened, Algeria's importance has become ever more important and it will really be a central focus in the talks between the secretary and president.
"There is a strong recognition that Algeria has to be a central part of the solution," said the US diplomat.
Clinton, on her second visit to the Algerian capital after a trip last year, is to meet President Bouteflika following talks with Foreign Minister Mourad Medelci.
The North African nation shares a long border with Mali, where extremists and rebel groups took over large parts of the country's north after a coup in March.
Mauritania and Algeria have called for dialogue in a bid to reach a political solution to the crisis, after initially ruling out sending troops.
The common influence among the fundamentalist armed groups ruling northern Mali is AQIM, which originated in Algeria and is active in regional countries including Mauritania.
The United Nations Security Council on October 12 approved a resolution urging West African nations to speed up preparations for an international military force of up to 3,000 troops that would attempt to reconquer northern Mali.
Algeria, with its powerful army, was at first opposed to any military intervention in Mali, with which it shares a 1,400-kilometre (870-mile) border, fearing a destabilisation of its territory.
And according to another State Department official travelling with Clinton, Algeria has been "warming to the idea" of intervention led by the Economic Community of West African States (ECOWAS).
"One of the things that we'll be talking about is... the role that Algeria could play if ECOWAS provides the boots on the ground... in coordination with the forces of Mali," said the official.
"Then the rest of us have to support that and create the means for it to succeed."