The letter issuing invitation to tender for multi-purpose combat aircraft for the Croatian Air Force, signed by the commission in charge of procuring the jets, was delivered to seven countries on Wednesday, the government said in a press release.

The invitations for the potential purchase of new aircraft were sent to the United States, for its F-16 jets, and to Sweden for the JAS Gripen aircraft. Five other invitations for used aircraft were sent to France for Rafale, Italy for Eurofigher, and Norway, Greece, and Israel – the latter three all for their own F-16 jets.

The new tender is Croatia’s second attempt to update its aging air force, launched 12 months after after the agreed deal to purchase twelve F-16 C/D Barak fighter jets from Israel, worth some 3.1 billion kuna ($477 million), had fallen through in January last year. Although the sale had been agreed with Israel, the sale was blocked by the United States before a single aircraft was delivered because the Israeli jets had after-market Israeli-made equipment installed.

The US, as the original manufacturer, must sign off on any deal before the aircraft are passed on to any third party, and it is US policy not to approve second-hand sales unless avionics installed are returned to their factory condition.

Croatia’s Air Force is in dire need of modernising its fleet, as its investory currently consists of only eight fighter jets, all of which are the outdated Soviet-made MiG-21s originally manufactured in the 1980s – with only four believed to be in operation.

Offers from interested countries for the fresh tender are expected to come in by May, after which a government commission is expected to spend three months reviewing offers before issuing its recommendation by August 2020.