US Secretary of State Hillary Clinton Monday pressed Algerian President Abdelaziz Bouteflika to support possible military action in neighbouring Mali, where Islamists control large areas of the north.
Algeria, with its powerful army and intelligence services after years of battling Islamist extremism, is seen by Washington as a key player although it is opposed to having direct military involvement in any intervention.
"We had a in-depth discussion of the region and particularly the situation in Mali," including the "terrorist and drug trafficking threat that is posed to the region and beyond," Clinton told reporters after her talks in Algiers.
She said they agreed to continue contacts and join regional states, the United Nations, African Union and the Economic Community of West Africa States (ECOWAS) "to determine the most effective approaches we should be taking."
The United States and France have launched a diplomatic offensive to secure Algerian backing for action in Mali after the UN Security Council urged ECOWAS to prepare a military force against Al-Qaeda in the Islamic Maghreb (AQIM) which is tightening its grip on the north.
The Security Council called on West African nations to step up such preparations to reconquer territory held by AQIM and other jihadist groups.
A US State Department official travelling with Clinton told reporters that Algeria, which shares a long border with Mali, had a "central" role to play in any intervention, noting its "intelligence-gathering" capability.
"Algeria being the strongest Sahel state became a critical partner in dealing with AQIM," since the Islamists spread their control over large swathes of northern Mali following a coup in March, the official said.
"Algeria has unique capabilities that no one else in the region really has... The strength of its military forces, its intelligence-gathering capability... So Algeria's central role in leading the fight against the AQIM is really central."
The official also noted that "counterterrorism has been a critical prism through which the Algerian-US bilateral relationship has been developing for some time."
Since April, AQIM and Tuareg allies Ansar Dine and the Movement for Oneness and Jihad in West Africa (MUJAO) have imposed Islamist sharia law in parts of Mali that they have effectively partitioned.
Algeria and Mauritania have both called for dialogue in a bid to reach a political solution.
The common influence among the fundamentalist armed groups ruling northern Mali is AQIM, which originated in Algeria and is active regionally, including in Mauritania.
At first Algeria staunchly opposed any military intervention in Mali, fearing a destabilisation of its territory, inhabited by 50,000 Tuaregs, but now it appears it could back an operation as long as it is African in nature and only if its own army is not directly involved.
The Security Council on October 12 approved a resolution urging ECOWAS to speed up preparations for a force of up to 3,000 troops that would attempt to recapture northern Mali.
It gave ECOWAS until November 26 to clarify its plans.
Another State Department official travelling with Clinton said Algeria has been "warming to the idea" of intervention led by West African states.
"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.
But US sources said that Bouteflika did not give a "concrete yes" or "no" to military intervention by ECOWAS.
An Algerian Tuareg chief, MP Mahmud Guemama, meanwhile spelled out why he opposed military intervention, in an interview with Elkhabar newspaper published on Monday.
"What the United States and France are asking will cause a lot of problems," he said, warning that such action had "colonial objectives."
"We are more concerned about Algerian towns in the Sahara than northern Mali," he said. "We know how military intention starts but never know the end. Libya was a good example."