State Department spokesperson Ned Price said US officials had communicated with their Tunisian counterparts on the importance of checks and balances in a democratic system.

He said the US government had called for an “inclusive and transparent reform process with input from civil society and diverse political voices to strengthen the legitimacy of reform efforts” in Tunisia.

Mr Saied has pushed through a series of moves expanding his powers and dismantling elected institutions since last year, when he suspended parliament.

On Wednesday he sacked 57 judges, accusing them of corruption and protecting terrorists.

Earlier last month, he announced a plan for a "new republic" in Tunisia which would be put to a referendum on 25 July.