The signing ceremony, broadcast on Iranian state television, was overseen by Iranian President Ebrahim Raisi and Venezuelan counterpart Nicolas Maduro and was held at Saadabad Palace in northern Tehran. The plan includes cooperation in the fields of oil, petrochemicals, defense, agriculture, tourism and culture. Sign up now for FREE unlimited access to Reuters.com Register It also includes repairing Venezuelan refineries and exporting technical and engineering services. “Venezuela has shown exemplary resistance to sanctions and threats from enemies and imperialists,” said Iranian Raisi. “The 20-year co-operation document is a testament to the two countries’ willingness to develop ties.” “Sanctions and threats against the Iranian nation over the past 40 years have been many, but the Iranian nation has turned these sanctions into an opportunity for the country to progress,” he said. Maduro said through an interpreter that a weekly flight from Caracas to Tehran would begin on July 18. In a meeting with Maduro, Supreme Leader Ayatollah Ali Khamenei promised that Iran would continue to support Venezuela in the face of US pressure, according to state media. “The successful experience of both countries has shown that resistance is the only way to deal with these pressures,” Khamenei said. “The two countries do not have such close ties with any other country and Iran has shown that it takes risks in times of danger and holds the hands of its friends.” Maduro said: “You helped us when the situation in Venezuela was very difficult and no country was helping us.” In defiance of US pressure, Iran has sent large shipments of fuel to Venezuela and helped repair refineries. Last month, Venezuela began importing Iranian heavy crude, expanding an exchange deal signed last year to exchange Iranian crude for Venezuela heavy crude oil. read more Maduro arrived in Tehran on Friday with a high-level political and economic delegation after visiting Turkey and Algeria. During the visit, Iran delivered to Venezuela the second of four Aframax-sized oil tankers with a capacity of 800,000 barrels ordered by the Iranian company SADRA, state media reported. SADRA has been under US sanctions for more than a decade for its ties to the Iranian Revolutionary Guards elite. In May, state-owned National Iranian Oil Engineering and Construction Co. signed a contract worth about 110 million euros to repair Venezuela’s smallest refinery at 146,000 barrels a day. Sign up now for FREE unlimited access to Reuters.com Register Report from the Dubai Newsroom. Editing by Jason Neely, Angus MacSwan and Diane Craft Our role models: The Thomson Reuters Trust Principles.