Israel agreed to sell military technology as well as anti-aircraft and missile defense systems to Azerbaijan, Israeli media reported on Sunday.

The Israeli state company Aerospace Industries concluded the contract, a deal worth some $1.4 billion, according to The Times of Israel.

Ties between Tehran and Baku have deteriorated in recent years. Last month, Azerbaijan said it thwarted a terrorist plot against Israel’s envoy in Baku by two people allegedly linked to Iran’s intelligence services.

Tehran later accused Azerbaijan, which borders Iran and has friendly relations with the United States and Israel, of colluding with Israeli intelligence services in the killing of an Iranian nuclear scientist in January.

Western nations suspect Iran, which is already under numerous international sanctions, of pursuing a secret nuclear weapons program but Tehran insists it needs nuclear power solely for civilian purposes.

Israel has persistently denied the connection between the next round of tensions in the Persian Gulf and military supplies to Azerbaijan. Israeli experts point out that such transactions are prepared months, even years ahead.