People hold Hezbollah flags during a rally in Tehran, Iran, June 1, in this photo provided by West Asia News Agency. Reuters-Yonhap

Iran has not yet responded to a proposed final agreement with the United States aimed at ending the conflict between the two countries, and discussions on the final text are continuing in Tehran, a source close to the Iranian negotiating team told Mehr News on Tuesday.

The source said Iran was reviewing the proposal cautiously because of what it sees as a history of U.S. non-compliance and longstanding mistrust.

"Based on previous experiences, Iran is seeking tangible and real benefits," the source said.