Washington, May 20, 2019, SPA -- 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, Reuters reported. "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. -- SPA 01:49 LOCAL TIME 22:49 GMT 0026 www.spa.gov.sa/w1105044