Iran said Wednesday that it has "serious concerns" about Israel's presence in the Caucasus, as tensions mount between Iran and Azerbaijan over Baku's ties with Israel, a major arms supplier.

The comments came a day after unconfirmed reports in Azerbaijani media said Iran has closed its airspace for Azerbaijani army aircraft.

"We certainly will not tolerate geopolitical change and map change in the Caucasus," Iranian Foreign Minister Hossein Amir-Abdollahian told reporters in Moscow.

"We have serious concerns about the presence of terrorists and Zionists in this region."

Since mid-September, tensions have soared between Iran and Azerbaijan, which share a 700-kilometre (430-mile) border.

Israel is a major arms supplier to Azerbaijan, which last year won a six-week war with neighbour Armenia over the disputed Nagorno-Karabakh region.

On Friday, Iranian ground forces began manoeuvres near the frontier, a move criticised by Azerbaijani President Ilham Aliyev.

The day before the drills were launched, Amir-Abdollahian told his Azerbaijani counterpart that Iran would not tolerate Israel's presence or activity "next to our borders" and vowed to take any necessary action.

Aliyev said Tuesday that Baku "will not leave unanswered" Tehran's "baseless" accusations of an Israeli military presence on its soil.

Also Wednesday, Azerbaijan's state-owned AZAL airlines said that it will start using Armenian airspace for flights. 

The move marked the first sign of easing tensions between Baku and Yerevan, days after the countries' leaders expressed readiness to meet for talks.