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.

Secretary of State Marco Rubio says Iran must give up all nuclear enrichment if it wants to make a deal during talks with the Trump administration and head off the threat of armed conflict

MUSCAT (Reuters) -Top Iranian and U.S. negotiators began a new round of indirect talks on Saturday to hammer out a deal curbing Tehran's 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.