U.S. President Donald Trump said Monday that Iran had agreed to extensive inspections of its weapons programs as part of efforts to ensure what he called "nuclear honesty," signaling a new phase in Washington's attempts to curb Tehran's nuclear ambitions through diplomacy.

"Everybody is fully aware that Iran will agree to have Major Weapons Inspections in order to ensure 'Nuclear Honesty' long into the future," Trump said in a post on his social media platform Truth Social.

This came hours after Vice President JD Vance said talks with Iran in Burgenstock, Switzerland, had produced a "very good foundation" for a final agreement and claimed that Tehran had agreed to allow inspectors from the International Atomic Energy Agency (IAEA) back into the country.

However, citing a source, the Iranian semi-official Fars news agency denied Vance's claim, saying no discussion took place during the recent Switzerland talks regarding the return of IAEA inspectors to Iran.

On June 14, Iran and the US announced they had reached a 14-point understanding through Pakistani mediation, aimed at ending the four-month war, reopening the Strait of Hormuz and setting a framework for nuclear negotiations.

The memorandum entered into force on June 18 after being electronically signed by Iranian President Masoud Pezeshkian and US President Donald Trump.