"There is not a single provision in this agreement that amounts to capitulation," Pezeshkian said in a speech published by state-run IRNA on Sunday.
"The supreme leader sets the policies, and we will follow that path."
The memorandum of understanding opened a 60-day period for talks aimed at ending the war and reaching an accord on Iran's nuclear program.
That period ended last week with no signs of compromise, especially on the crucial issue of reopening the Strait of Hormuz that is vital to global shipping.
Pezeshkian said the country cannot attract investment in this stalled phase.
Nearly six months after the war began, Iran's economy is suffering under sanctions and a US naval blockade.
Hard-line leader of Iran's Supreme National Security Council Mohsen Rezaei, in his most extensive public comments since being named to the post this month, warned neighbouring countries against joining a new US effort to hurt Iran's economy and said they would be considered enemies.
"If (US President Donald Trump) wants to do something, we will retaliate in a seismic manner," Rezaei told the state broadcaster in an interview that aired late on Saturday.
He said Iran would target oil-shipping routes out of the Persian Gulf - alternatives to the Strait of Hormuz - if neighbors join in.
Rezaei, a former Revolutionary Guard commander and military adviser to Supreme Leader Ayatollah Mojtaba Khamenei, was part of senior appointments widely seen as hardening Iran's political and military stance.
There were no confirmed attacks in the Strait of Hormuz over the past 48 hours, a multinational coalition overseen by the US navy said on Sunday, with shipping traffic still at reduced levels.
Pakistani Field Marshal Asim Munir will lead a delegation to Tehran on Monday, Iranian state television reported, citing Iran's foreign ministry spokesman Esmail Baghaei.
Two regional officials said the visit was part of Pakistan's efforts to de-escalate tensions between the United States and Iran and urge them to return to the negotiating table.
