Iranian President Ebrahim Raisi held talks in Tehran on Monday with Tajik President Emomali Rahmon.
Discussions focused on the situation in neighboring Afghanistan.
Raisi said both countries want stability and security in Afghanistan and throughout the region and consider the presence of terrorists in this country very worrying.
The two parties signed cooperation agreements in various fields less than two weeks after the inauguration of an Iranian factory for military drones in Tajikistan.
Iran and Tajikistan agree on the issue of Afghanistan and that an inclusive government should be formed, said Raisi.
He stressed that Iran and Tajikistan "believe that the outsiders and the evil hands of arrogance that strengthen ISIS and terrorist groups in the region do not even think about the security of the people of Afghanistan and the region, and they are only pursuing their own political goals and interests."
"Evidence of this was the 20-year presence of NATO and the United States in Afghanistan, which resulted in nothing but war, bloodshed, and destruction for the country," he added.
Raisi had traveled to Dushanbe in September on his first foreign visit.
Raisi said his visit helped increase trade relations between the two countries fourfold.
During Rahmon's visit, senior Iranian and Tajik officials Iran signed 17 documents of cooperation in politics, economy, trade, transportation, investment, new technologies, environment, sports, energy, judiciary, education and research, and tourism in the presence of the two presidents.
Raisi said the agreements are a "turning point in strengthening and deepening relations between the two countries."
On May 17, Iran's Chief of Staff Mohammad Bagheri visited Dushanbe and inaugurated a drone factory, "Ababil 2," to produce UAVs capable of flying for about 90 minutes with a range of 150 km.
It was the first time Iran publicly announced the manufacture of weapons and drones outside its territory, which is seen as an attempt to establish a balance of power in the region, especially after the Taliban took control of Afghanistan.
In January, Pakistan's "The Frontier Post" revealed that the US is trying to persuade the governments of Tajikistan and Uzbekistan to set up military bases in their territories for possible special operations in Afghanistan, including drones and units to assess intelligence data.