June 18 (Reuters) - Iran's Supreme Leader Mojtaba Khamenei said on Thursday he had authorised a memorandum of understanding signed by the Iranian and U.S. presidents, despite holding a different view, after receiving assurances from President Masoud Pezeshkian and other senior officials that Iran's rights and the interests of the "Resistance Front" would be safeguarded.

In a written message to the Iranian nation, Khamenei said Pezeshkian, in his capacity as head of the Supreme National Security Council, had accepted responsibility for ensuring the agreement protected Iran's interests and pledged not to yield if Washington made what he described as excessive demands.

Khamenei added that future face-to-face negotiations with the United States would not mean accepting "the enemy's position".

(Reporting by Enas Alashray, Yomna Ehab and Elwely Elwelly; Editing by Alex Richardson)