WASHINGTON, Aug 3 (Reuters) - U.S. President Donald Trump on Monday said Iran faced "decapitation" if it did not agree a pact to end the conflict between the two nations, saying Tehran had one last chance to strike a deal."I think we're going to maybe get something, but I want to give them every last chance before decapitation," he said, reiterating a threat to launch a major attack on Iran. Earlier on Monday, after Iran said there were no talks under way, Trump slammed what he called Iran's "unbelievably duplicitous" leadership.

Remarks come despite Trump saying an agreement with Iran is imminent with negotiations set to begin on Monday.

US President Donald Trump has said the US is holding negotiations with Iran, while Tehran denies any talks are taking place and insists it is only holding discussions with Oman…

President Trump stated that talks with Iran are currently underway at Tehran's request. These discussions represent Iran's final opportunity to secure a favorable agreement. The…