The tankers are carrying around 1.53 million barrels of gasoline and alkylate to Venezuela, according to both governments, sources and calculations made by TankerTrackers.com based on the vessels' draft levels.
Rouhani underlined that regional security is of the most significant issues to Iran adding that "the United States has sowed insecurity in various parts of the world but Iran is not interested in tension or confrontation".
The remarks come after The Wall Street Journal cited unnamed USA officials as saying on Wednesday that the Trump administration is considering new sanctions and "other legal steps to disrupt Iranian oil exports to Venezuela", in response to what Washington sees as Tehran's attempts "to make inroads into Latin America". Washington is considering measures in response, according to a senior United States official, who did not elaborate on any options being weighed.
Venezuela's defence minister said the military will escort the tankers once they reach the nation's exclusive economic zone.
"We have continued to say that Iran and Venezuela - both two outliers in the worldwide order - (are) clearly violating global sanctions on both nations with this transaction", he told reporters.
Five tankers transporting 1.5 million barrels of Iranian fuel to Venezuela are now near the Caribbean, with the first ship scheduled to reach the country's territorial waters by Sunday. It has been navigating with its satellite signal on since it passed the Suez Canal earlier in May.
A force of U.S. vessels, including Navy destroyers and other combat ships, patrol the Caribbean on what USA officials call a drug interdiction mission.
PDVSA did not immediately reply to a request for comment.
This followed Iranian Foreign Ministry spokesman Abbas Mousavi warning late last week that the USA may "suffer repercussions that arise out of any unthinking measure [that it could take]" against Venezuelan-bound Iranian fuel tankers.
Fuel sales at stations declined to about 40,000 bpd due to rationing, according to independent calculations.
A U.S. Treasury Department spokesperson told The Wall Street Journal on Wednesday that the department "will continue to aggressively use its sanctions authorities to target malign activity and sanctions evasion", and that anyone who works with Venezuela's oil business could be sanctioned by the United States.
The five Iranian tankers now on the high seas are expected to start arriving in Venezuela in the coming days. "And we will not fall prey to the UNC "call" for sanctions against TT".