UNITED NATIONS - The U.N. Security Council will soon begin discussing a possible United Nations peacekeeping force for Mali, an idea the world body had been uncomfortable with before France's recent military intervention, envoys said on Wednesday.

Last month, the 15-nation council approved an African-led force for Mali that likely would have been funded and trained by the European Union. That force would not have begun operations until late this year against Islamist militants who took control of a vast region of northern Mali last year.

However, France's military intervention this month against the militants in the West African nation rendered that plan moot, diplomats said.

"There is increasing talk of moving straight to a U.N. peacekeeping operation," a senior Western diplomat said on condition of anonymity. Another diplomat and a U.N. official confirmed that, saying the discussions would begin within days.

It is an issue that U.S. Ambassador to the United Nations Susan Rice first mentioned last week during a Security Council meeting. Other council members are now warming to the idea, the diplomats and U.N. officials said.

Deployment of a U.N. peacekeeping force would require Security Council approval. Another option would be to send in an African Union force mandated by the council with logistical and other support from the United Nations, similar to the AU's Somalia mission.

Washington favors a U.N. mission rather than an AU force, diplomats said.

Details would have to be worked out but one idea floated was for U.N. peacekeeping force of some 3,000 to 5,000 troops, diplomats said. They noted, however, that since the three-week-old conflict is continuing, it is still too early to deploy peacekeepers.

"There's no peace to keep yet," said one diplomat. "We're still in the peace-enforcement phase."

Secretary-General Ban Ki-moon had been uncomfortable with direct U.N. involvement in the proposed African-led operation, diplomats said, because it would have been an offensive combat mission - not peacekeeping.

But now that the French-backed Malian army has retaken most of the desert nation's cities, the possibility of deploying U.N. peacekeepers has become less remote, the envoys said.

They said a U.N. peacekeeping force would offer certain advantages over the African-led force approved by the council last month. Funding would be clear, it would be easier to monitor human rights compliance and the United Nations could choose which national contingents to use in the force.

Many of the African troops already in Mali supporting the French and Malian militaries could theoretically remain and become part of a U.N. peacekeeping force, one diplomat said.

It is an idea France would likely support. Prime Minister Jean-Marc Ayrault said on Tuesday that Paris would favor a quick deployment of international monitors to Mali to ensure human rights are not abused.