Azerbaijan and Iran have reached an agreement to trade natural gas with Turkmenistan, cementing their economic reconciliation just months after a major political crisis between the two neighbours.

The deal was concluded when the presidents of Azerbaijan and Iran met in Ashgabat on November 28.

“From now on, Iranian-Azerbaijani relations will develop in all areas,” Azerbaijan President Ilham Aliyev told following the signing. “Our peoples are fraternal peoples, our countries are fraternal countries, and the issues discussed today show again that Iranian-Azerbaijani relations are at a very high level.”

It was a dramatic contrast to the sabre-rattling of Aliyev and other Azerbaijani authorities less than two months prior, when they were pouring vitriol on Iran amid a crisis sparked by Azerbaijani police detaining two Iranian truck drivers. Baku hinted at fuelling separatist feelings among Iran's sizeable ethnic Azerbaijani minority by organizing unprecedented military drills on the border with Azerbaijan.

But the two countries quickly patched things up, signing a potentially substantial pact on energy cooperation in late November, while many specifics remained unknown.

The new gas swap agreement clarified one of the fundamental components of the accord. It will carry 1.5 to 2 billion cubic meters of gas each year, with Turkmenistan supplying gas to Iran and Iran delivering an equal quantity of gas to Azerbaijan independently.

The discussions on the new deal began "approximately two months ago," according to Iranian Petroleum Minister Javad Owji, amid the height of the political turmoil. He stated that shipments will commence on December 22.

“Our relations with the Republic of Azerbaijan are not only neighbourly, they are [also] relations of our hearts. The hearts of the peoples of the two countries beat together,” Iranian President Ebrahim Raisi said at the joint appearance with Aliyev. “We must never allow others to interfere in our relations. We must resolve our own problems, work together to advance our relations, and deepen mutually beneficial cooperation. Experience so far shows that when we discuss our issues ourselves, we manage to resolve many of them.”

Despite their involvement in the accord, Turkmen officials appeared to be missing from the signing. The accord was not included in the official Turkmenistan government readout of President Gurbanguly Berdymukhammedov's meeting with Aliyev, nor in Berdymukhammedov's meeting with Raisi.