WASHINGTON — France is appealing to President Donald Trump not to cut off U.S. military support to French forces fighting Islamist militants in Africa, warning that it could undermine efforts to counter a growing terrorist threat in the Sahel region.

Trump administration officials, however, are skeptical of the French counterterrorism mission's value and have refused so far to promise continued logistical and intelligence support that French forces rely on in their fight against al Qaeda and ISIS-linked groups, according to one current and one former U.S. official.

"We're spending hundreds of millions of dollars on a French force that has not been able to turn the tide," said a senior administration official, who was not authorized to speak on the record.

"It's not even a case of whack a mole. For all that we're spending, we're not getting much out of it," the official told NBC News.

The U.S. provides French forces with plane refueling and intelligence from drones at a relatively modest cost out of the Pentagon's vast budget. The administration has been reviewing its options, including possibly requiring France to reimburse the U.S. for the drone flights and refueling services, the official said.

In a statement, a Pentagon spokesperson said, "The United States and France have an enduring partnership that spans many efforts globally. We maintain an open dialogue about future requirements and resourcing in Africa and other regions."

The White House and the State Department declined to comment.

From bases in Niger, the U.S. military's drone flights have delivered crucial intelligence and surveillance over a vast expanse in the Sahel, helping 4,500 French troops hunt down al Qaeda and ISIS-affiliated fighters. And U.S. air-to-air refueling tankers have helped keep French aircraft in the air.

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But the French have faced mounting challenges in the Sahel, including the collision last year of two French helicopters in northern Mali that claimed the lives of 13 troops. Terrorism has dramatically increased in the region in recent years, with the number of attacks roughly doubling annually since 2016, according to the Africa Center for Strategic Studies. While French troops were greeted by cheering crowds when they arrived in Mali in 2013, protesters recently have burned the French flag and demanded the troops leave.

French President Emmanuel Macron has called for a stronger international element to the counterterrorism fight and is pushing hard to persuade the Trump White House to continue to provide drones and refueling.

Macron sent his national security adviser to Washington last week to make the case, a French official said. A delegation led by his Africa adviser, Franck Paris, met their American counterparts on Thursday, Jan. 23, and French Defense Minister Florence Parly is due to hold talks at the Pentagon on Monday, Jan. 27, the official said.

"If the Americans were to decide to leave Africa it would be really bad news for us. I hope to be able to convince President Trump that the fight against terrorism also plays out in this region," Macron said earlier this month.

The French president made the comment after a summit in southwestern France of leaders of a coalition of five Sahel countries — Mali, Niger, Burkina Faso, Chad and Mauritania. The heads of state endorsed a continued French military presence, despite recent anti-French street protests, and also called on Washington to keep up its military support.

The five leaders expressed "gratitude for the crucial support provided by the United States and expressed the wish for its continuity."

A strategic shift

The French plea for continued assistance with its Sahel mission comes as the Trump administration is weighing a wider drawdown of U.S. forces in Africa, as part of a strategic shift away from a global war on terrorism to countering "great power" threats posed by Russia and China.

Although some U.S. officials are impatient with the French operation, the administration is debating more broadly whether Africa should be treated as a high national security priority or whether military and intelligence resources should be deployed elsewhere in the world, said Judd Devermont, who served as the national intelligence officer for Africa until 2018.

"What I think is happening right now is less of a question about the efficacy of the French mission, but more of a bigger question — does the U.S. have national security interests in the Sahel, in the counterterrorism fight?" said Devermont, now at the Center for Strategic and International Studies.

French Minister of Army Forces Florence Parly meets French officers of the Barkhane counterterrorism operation in Africa's Sahel region, at the Barkhane base near Niamey in Niger on July 31, 2017. Boureima Hama / AFP - Getty Images file

Lawmakers from both sides of the aisle have pushed back over the Pentagon's proposals to scale back the U.S. military's presence in the Sahel and elsewhere in Africa, warning the move would open a vacuum that could be exploited by terrorist groups as well as Russia and China.

A drawdown "could result in further instability on the continent and serve to strengthen terrorist groups that could target the homeland," said a joint letter this month from Republican Sen. Lindsey Graham of South Carolina and Democratic Sen. Chris Coons of Delaware.

The two senators specifically cited the Sahel as a crucial strategic area to combat terrorism. "Our European partners, such as France, rely on our intelligence and logistic support for operations within West Africa," the senators wrote.

Seth Jones, a former adviser to the U.S. military and an expert on counterterrorism threats, said the French operation has produced mixed results but was still an important tool to stem the spread of extremist violence.

"The French are basically all we have," Jones said. "The U.S. can complain how well the French are doing. But the French are all that stands between anarchy and some modicum of stability."