The United States has raised strong doubts that a planned African-led intervention force will be tough enough to tackle Al-Qaeda linked militants in Mali, diplomats said.
The United States is expected to become a major financier of any operation to oust militant Islamists and rebels who have taken over much of the West African nation and imposed a brutal rule.
Its military objections have made UN Security Council talks on the crisis more tense, diplomats said. France, main western backer of the African force, remains confident however that a resolution approving action will be passed this month.
The current plan is for the Economic Community of West African States (ECOWAS) to provide 3,300 troops to help Mali's crippled military attack the rebels in the north of the country.
US ambassador Susan Rice has argued however that the west African troops are ill-suited for the desert battle against Al-Qaeda in the Islamic Maghreb (AQIM) and its ally, the Movement for Oneness and Jihad in West Africa (MUJAO), UN diplomats who took part in council negotiations told AFP.
"She has argued that this should be a counter-terrorist operation and the fighters who take them on must have that background," one diplomat said.
Johnnie Carson, US assistant secretary of state for African affairs, outlined a long list of US "key questions" about the force to a House of Representatives foreign affairs sub-committee on Wednesday.
These include the "necessary force levels, the capabilities of the Malian and international forces to accomplish the objectives of the mission, cost and funding needs, logistical requirements, operational timelines, planning for minimizing impacts on civilian security and the humanitarian situation," he said.
The United States, United Nations and other countries have also said a strong emphasis must be put on political negotiations before the military move in.
Carson said US military planners are helping ECOWAS with their intervention plan and US officials stress that Washington shares international fears over the rebels.
Tuareg rebels and the Islamist groups seized on the chaos caused by a military coup in Mali in March to take over almost half the country. They have since imposed a brutal Islamic law, carrying out floggings and executions and destroying Muslim shrines in the holy city of Timbuktu. But they are also fighting each other.
During consultations of the 15-nation Security Council on Wednesday, France and African nations pressed for a speedy approval of an authorization resolution.
A Mali government minister said deployment of the international force has become urgent because of the suffering being inflicted by the Islamists.
But US ambassador Rice is "highly skeptical" of the West African plan, one UN diplomat said. "There is little trust in the African troop contributors, that they can do the job, and there was little trust in the Mali army."
Rice insisted there must be a "credible" force that "must kick Al-Qaeda hard," added a second diplomat. She suggested that troops from Chad, experienced in desert warfare, could be sent.
France, Germany and the United States are ready to send trainers to Mali. While some UN officials have spoken of a possible operation next September, US officials have indicated it could take at least a year just to train the Malian army.
There are also questions about the financing, which the UN leader Ban Ki-moon has said the United Nations cannot provide.
The first year will cost between 200 million and 500 million dollars, according to various diplomats. The European Union, United States and France are expected to be the main non-UN financiers.
An international fund, similar to one used to finance the African force in Somalia, could also be set up, diplomats said.
On the Security Council, Germany, France, Russia and China back force approval but the US stance could make talks "complicated", one diplomat said.
"We are at the beginning of a long and maybe winding and difficult road towards a resolution," said another.© ANP/AFP