US has been providing military and logistics support to France from at least 2013 to present in North Africa (Mali/Niger) including aerial refueling and transport.
Literally any operation done involving European troops involves the US because other nations are significantly under-invested with limited logistics, special systems and transport capabilities. It’s what sets the US apart from every nation including China and Russia. They all lack the core capabilities required to maintain foreign operational tempo.
https://thehill.com/policy/defense/409468-mattis-us-not-planning-to-cut-back-one-bit-of-support-for-french-operations-in
"France has about 4,000 troops in Mali leading operations against militants linked to al Qaeda and the Islamic State in Iraq and Syria. The French forces in Mali were those who came to the rescue of U.S. troops in Niger during the 2017 ambush.
The U.S. supports the French effort with intelligence, surveillance and logistics such as refueling and transportation. U.S. funding for regional French-led operations is about $46 million in the latest budget."
http://www.thedrive.com/the-war-zone/15431/just-how-closely-are-us-and-french-forces-cooperating-in-niger
"In addition to U.S. Air Force personnel who managed the influx of personnel and cargo in Mali’s capital Bamako, U.S. special operators flew into Mali on small, specialized U.S. Air Force transport aircraft with discreet civilian-style paint jobs to directly assist French forces on the ground. According to one official history that the author obtained via the Freedom of Information Act, the C-146A Wolfhound, a militarized version of the twin engine Dornier 328, was particularly important.
“The C-146A proved instrumental and provided U.S. support to the French counter-offensive,” the 524th Special Operations Squadron explained in a review of its activities during 2013. “The C-146A was also the first U.S. aircraft to land in Gao [, a major city in Northern Mali,] following the offensive against Al Qaeda in the Islamic Maghreb, delivering U.S. special operations forces to the frontlines of conflict.
This support has been constant ever since and has continued in response to French requests. The U.S. military itself had suggested it would’ve preferred to end the partnership entirely years ago.
In January 2014, Defense Department spokesman U.S. Air Force Major Robert Firman told Stars and Stripes “the Pentagon does not expect it to go on indefinitely.” “So, we’re hoping to continue to see, obviously, the French success there and hopefully our mission will continue to slow down,” U.S. Air Force Major Nicholas Schindler, then commander of the 351st Expeditionary Air Refueling Squadron in Moron, Spain, also told the outlet at the time."