Belgium is exploring the legal status of a last-minute French response to its request for proposals covering the acquisition of new combat aircraft.
In a letter from Florence Parly, the French armed forces minister, to her Belgian counterpart, Steven Vandeput, on 7 September, she promised to create a "deep partnership" between the two countries if the Dassault Rafale is selected for the 34-unit deal.
To take the form of a bilateral agreement, the collaboration would include a deeper industrial and technical contribution to the Rafale programme, as well as "in-depth co-operation" between the air forces of both nations in operations, training and support.
However, the Belgian defence ministry confirms that aside from the letter from Parly, there has been no formal response from the French side.
"Two offers have been introduced following the procedures, and there is this letter. We need to investigate what it means; we have asked for an offer and got a letter," says the defence ministry.
It is seeking clarity on the "legal status" of the letter, it says.
The two concrete responses are from the governments of the UK and USA, respectively bidding the Eurofighter Typhoon and Lockheed Martin F-35.
Belgium will now analyse those bids, ahead of a mid-February 2018 deadline for the submission of best and final offers; it hopes to be in a position to select the winning type in mid-2018.
Brussels intends to acquire the new aircraft in several batches as it progressively retires the 59 Lockheed Martin F-16A/Bs operated by the Belgian Air Component.