Croatia has urged Israel to say whether it can carry out a deal to deliver 12 used F-16 fighter jets or the purchase will be annulled.
Croatia's Defence Ministry said Thursday it needs an answer by January 11.
The tentative USD 500 million deal to buy the upgraded F-16 Barak fighter jets from Israel was made in March last year pending US approval allowing Israel to sell the American-made jets to a third party.
The deal ran into trouble after the US Congress hinted that Israel needs to strip off the upgrades that were added after Israel bought the planes from the US some 30 years ago.
Israel has upgraded the jets with sophisticated electronic systems, which was crucial in Croatia's decision to buy the planes from Israel rather than from the US.