"The negotiations are proceeding in an orderly and constructive manner, and I have informed my representatives not to rush into a deal in that time is on our side," Trump wrote on his Truth Social account.

"The Blockade will remain in full force and effect until an agreement is reached, certified, and signed."

The United States has imposed a blockade of Iranian ports since April 13 after Tehran virtually halted traffic through the economically vital Strait of Hormuz in response to the US-Israeli attacks on Iran that began February 28.

Trump's comments came as bipartisan opposition mounted in Washington overnight with several current and former lawmakers and officials criticizing supposed aspects of the deal that began to leak.

"Both sides must take their time and get it right," Trump wrote in the same Truth Social post, while slamming the 2015 nuclear deal that former president Barack Obama agreed with Iran.

While the White House has not released aspects of the deal, Iran Foreign Ministry spokesman Esmaeil Baqaei said Saturday on state television that the two sides were nearing a "a memorandum of understanding, a kind of framework agreement composed of 14 clauses," in "a trend toward rapprochement."

Later on Saturday, Trump wrote on Truth Social that an agreement was "largely negotiated" but "subject to finalization."