Israeli Prime Minister Benjamin Netanyahu has urged US President Donald Trump not to approve the sale of advanced American military equipment to Turkey, arguing that providing Ankara with F-35 fighter jets or engines for its indigenous KAAN fighter would alter the regional balance of power.

According to Axios and Israel’s Channel 12, Netanyahu raised the issue during a phone call with Trump on Friday. The reports state that Netanyahu asked the United States to refrain from supplying Turkey with weapons systems intended to modernize the Turkish Air Force.

The issue comes ahead of Trump’s visit to Turkey for the NATO leaders’ summit in Ankara, where he is expected to meet Turkish President Recep Tayyip Erdoğan. Among the topics expected to be discussed are a reported $700 million agreement for the sale of F110 fighter jet engines manufactured by General Electric and the possibility of Turkey’s return to the F-35 program.

Israeli and US officials quoted in the reports said Netanyahu expressed concern over statements by Erdoğan and other Turkish officials regarding Israel.

In an interview with Fox News, Netanyahu argued that Turkey “does not deserve” to receive F-35 fighter jets or engines for its domestically developed KAAN fighter aircraft.