Trump threatens of strikes on Iran's bridges, power plants if Tehran rejects talks

US President Donald Trump has warned that the United States could launch strikes on Iran's bridges and power plants as early as next week if Tehran refuses to return to the negotiating table.

Speaking in an interview with Fox News, Trump said Iran faces "a very bad week" if it rejects diplomacy.

"If they don't come back to the table, we'll destroy their power plants and bridges," he said, adding that attacks on Iran's energy infrastructure remain "a last resort" but would be considered if necessary.

He also announced plans to reimpose a naval blockade on Iranian ports.

Trump claimed US negotiators had delivered a clear message to Tehran on Tuesday, warning that failure to reach an agreement would bring tougher consequences.

The US president, however, backed away from his earlier proposal to impose a 20 per cent transit fee on all commercial vessels passing through the Strait of Hormuz. Instead, he said Washington would pursue broader trade and investment agreements with Gulf states while moving ahead with renewed naval restrictions on Iranian ports.