ANKARA, Turkey (AP) — Turkey and Britain on Wednesday signed a preliminary agreement for the sale of Eurofighter Typhoon fighter jets to Turkey, a significant step in Ankara’s efforts to modernize its air fleet.

Britain signed a preliminary deal allowing Ankara to operate the jets while Germany approved delivery of 40 of them to Turkey, which has relied on both foreign purchases and its own defence industry projects, including domestic jets, to ramp up deterrence. Beyond the Eurofighters, Ankara is also in talks with Washington to purchase 40 F-16s.

Turkey and Britain have signed a memorandum of understanding to allow Ankara to be a user of Eurofighter Typhoon fighters, in a big step toward securing the procurement of the jets over which Turkey has been negotiating for years.