Iran will react decisively to any border threats, IRGC chief warns

"Our red line is sustainable security and any insecurity and threat in borders that harms our dear people's security and peace of mind is not acceptable," Salami said as he visited border areas of Iran's northeastern region.

He said Iran is determined to strengthen its defense and security measures to preserve security at the border areas which are close to the Armenian-Azerbaijani conflict zone.

Since late September, heavy clashes have been underway between Azerbaijani and Armenian military forces over the Nagorno-Karabakh region. Both sides blame each other for initiating the fighting in the Caucasus Mountains.

It has been the worst spate of fighting between the two former Soviet republics since the 1990s.

Salami's comments came after the Iranian Armed Forces warned the warring sides of a tough response if its border security is threatened.

Brigadier General Abolfazl Shekarchi, the spokesman of the Iranian Armed Forces, said in late October that “while strengthening defensive [measures] in Iran’s borderlines, the Armed Forces of the Islamic Republic announce that security in the border areas and of the Iranian people is their red line.”

Elsewhere in his Thursday remarks, the IRGC’s chief commander said, “Sustainable security is our red line and any form of insecurity and threat along borders, which would harm security and peace of mind of our dear people, would be unacceptable.”

Meanwhile, Iran's Supreme Leader Ayatollah Ali Khamenei has voiced regret over the "bitter incident" between the two sides, suggesting that the main solution to the problem is a return of all occupied lands of Azerbaijan by Armenia and “this must be done and international borders must be respected.”

However, the security of ethnic Armenians in the occupied region of Nagorno-Karabakh must be protected, Ayatollah Khamenei said in remarks on Tuesday.

The ayatollah also warned, "Terrorists who, based on reliable reports, have entered the region should avoid approaching the Iranian border, and if they do approach the border, they will definitely be dealt with decisively.” 

In response, Azerbaijan's Deputy Foreign Minister Khalaf Khalafov thanked Ayatollah Khamenei for supporting Baku's standing on the Nagorno-Karabakh conflict.

In a phone conversation with Iran's ambassador to Baku on Tuesday, Khalaf Khalafov expressed his country's appreciation for Ayatollah Khamenei's "important and fair" remarks which were based on "friendship and brotherhood" between the two neighboring countries.

He also described as important the Iranian special envoy's trip and Iran's regional initiative to resolve the crisis.