sentences:  After these threats to disrupt Iranian fuel tankers heading for Venezuela, Foreign Minister Mohammad Javad Zarif sent a letter to Antonio Guterres to warn about the US move to send troops to the Caribbean to obstruct the fuel export.Also Abbas Araghchi summoned Swiss ambassador as protector of US interests in Iran, urging him to convey Iran's serious warning about any possible threats by the US against Iranian tankers.The good cooperation between the two countries also expands in cultural and scientific fields in addition to the economic domains.