The third round of talks in three weeks raised hopes for an Iran nuclear accord, which could avert a new Mideast conflict. President Trump said he believed a deal was within reach.

Top Iranian and U.S. negotiators will meet again on Saturday to hammer out a new deal curbing Tehran's advancing nuclear programme, while U.S. President Donald Trump signalled confidence in clinching a new pact that would block Iran's path to a nuclear bomb.

The United States and Iran have begun a third round of nuclear talks, entering what experts describe as a more difficult phase of technical negotiations this weekend as Washington lays out its conditions.