Iranian President Ebrahim Raisi (L) and Venezuelan President Nicolas Maduro wave during Raisi s welcoming ceremony at Miraflores Presidential Palace in Caracas, on June 12, 2023. AFP
Raisi was welcomed in Caracas by Foreign Minister Yvan Gil, and was due to meet President Nicolas Maduro later in the day.
Before departing Tehran, Raisi had said his visit was at the invitation of the presidents of "friendly countries" Venezuela, Nicaragua and Cuba who, like Iran and Venezuela, are all the target of US sanctions.
"We have common interests, common visions, and common enemies," the president said, without specifying, in remarks to the press alongside Venezuelan leader Nicolas Maduro.
"The relationship between Iran and Venezuela is not a normal diplomatic relationship, but a strategic relationship," he added.
Tehran is one of the principal international allies of Maduro's government, which, like those in Cuba and Nicaragua, are also allies of Russia, an international pariah since the outbreak of the war in Ukraine last year.
"Iran is playing a starring role as one of the most important emerging powers in the new world," said Maduro, claiming that "together we will be invincible."
Part of the reason for Raisi's trip was to increase trade between the two countries, Raisi said, up from the current $3 billion a year to eventually $20 billion.
The two leaders announced that they signed 25 accords, across sectors ranging from education and health to mining.
Also on the agenda is developing technological cooperation between the two countries, part of Raisi's goal of improving "economic, political and scientific cooperation" between Iran, Venezuela, Nicaragua and Cuba.
"Over the last two years, our cooperation with these countries has developed," Raisi told the Irna news agency before he set off from Tehran.
Iran and Venezuela are also members of the OPEC oil cartel, which has become central to international discussions on the energy crisis sparked by Russia's war on Ukraine.
The war has renewed global efforts to solve Venezuela's ongoing political and economic crisis.
Last year, the US sent delegates to Caracas to meet Maduro, and after talks resumed between his government and the opposition in November, Washington granted a six-month license to US energy giant Chevron to operate in Venezuela.
The South American country, facing a deep economic crisis, has the world's largest oil reserves.
Raisi's trip follows a previous diplomatic visit by Maduro, who visited Iran in June 2022 and signed a 20-year pact to open "major fronts" for cooperation in the oil, petrochemicals and defense sectors.
In February, Iranian Foreign Minister Hossein Amir-Abdollahian visited Caracas and discussed with Maduro the "defense of their national interests faced with external pressures," according to Tehran.
In 2020, Iran sent 1.5 million barrels of fuel to Venezuela along with supplies to help restart struggling refineries. Washington has since accused Iran of circumventing sanctions.
The last Iranian president to visit Cuba and Venezuela was Hassan Rouhani in September 2016. Mahmoud Ahmadinejad made the last presidential visit to Nicaragua in 2007.
Daniel Ortega, the Nicaraguan president, defended Iran's right to acquire nuclear weapons in February.