A Saudi-led bloc of Arab states hostile to Qatar took aim today at Kuwaiti mediation and maintained a tough line.<br/>'<br/>In a joint statement in Riyadh today, the Saudi-led bloc showed no signs of backing down and said that dialogue on the implementation of the demands should not be preceded by any conditions.<br/>'<br/>Saudi Arabia led the United Arab Emirates, Egypt and Bahrain in cutting ties with Qatar in June, accusing it of<br/>bankrolling Islamist extremist groups and of being too close to Iran.The gas-rich emirate denies the claims and accuses the four countries of attacking its sovereignty.'<br/><br/>Kuwait has emerged as a key mediator in the crisis, while the United States has given mixed signals on its policy. Riyadh and Doha are both key allies of the United States.