US and Iran ceasefire set to expire this week, with Trump saying envoys will travel to Pakistan for new talks.
Iran rejected a second round, citing excessive US demands, shifting positions, and a naval blockade it deems illegal.
US warship seized Iranian cargo vessel TOUSKA in Gulf of Oman, Marines took custody after crew refused to stop.
Oil prices rose as tensions revived, after earlier slump from hopes of Strait of Hormuz reopening.