March 24 (Reuters) - The United States will continue its strikes on Iran, with the pause applying only to attacks on Tehran's energy sites, Semafor reported on Monday, citing a U.S. official, during what President Donald Trump has described as "productive" talks with unidentified Iranian officials.

Earlier on Monday, Trump had postponed for five days a plan to hit Iran's energy grid. Iran later denied that it had engaged in negotiations with the United States.

"The stop on attacks for five days is only on their energy sites," a U.S. official told Semafor.

"It is not on the military sites and the navy, and the ballistic missiles, and the defense industrial base. The initial initiatives of (Operation) Epic Fury will continue," he told the news agency.

Reuters could not immediately verify the report. The White House, the U.S. State Department and the Pentagon and the did not immediately respond to a request for comment outside regular hours.

The Semafor report also added that Israel was not party to Washington's talks with Tehran.

(Reporting by Ruchika Khanna in Bengaluru; Editing by Lincoln Feast.)