Trump threatens Iran in tweet as tension between two countries escalate

WASHINGTON (Reuters) - U.S. President Donald Trump threatened Iran in a tweet on Sunday, raising concerns about a potential U.S.-Iran conflict at a time when tensions between Washington and Tehran have risen.

"If Iran wants to fight, that will be the official end of Iran. Never threaten the United States again," Trump said in a tweet.

Trump has tightened economic sanctions against Iran, and his administration says it has built up the U.S. military presence in the region. It accuses Iran of threats to U.S. troops and interests.

Tehran has described U.S. moves as "psychological warfare" and a "political game."

(Reporting by Nandita Bose; Editing by Sandra Maler)