America's Rex Tillerson says Qatar has fulfilled its commitments, appoints new Gulf envoy

Qatar is fulfilling its commitments under an agreement Doha reached with the US on fighting terrorism financing, the US secretary of state has declared, as the blockade of Qatar by four Arab countries remains in place.

"We are committed to seeing this dispute resolved," Rex Tillerson said in reference to the ongoing crisis, adding that the US sees it as "important to the fight against terrorism."

Speaking at a wide-ranging press briefing, the top US diplomat also said he was sending former head of Central Command, retired General Anthony Zinni, to the Middle East to help resolve the standoff between the US' Gulf allies that led Saudi Arabia, Bahrain, Egypt and the UAE to cut ties with Qatar and accuse Doha of supporting terrorism. Doha denies the charges.

Zinni will go to the region "so we can maintain a constant pressure on the ground," Tillerson said. "There's only so much you can do with telephone persuasion."

The issue became a major headache for the Trump administration because the largest US base in the Middle East is based in Qatar, home to nearlu 10,000 troops.

Donald Trump initially suggested he was closer to the Saudi position, but the US Department of Defence and Tillerson's State Department have since put their weight behind a Kuwaiti mediation effort, urging an end to the blockade and describing Doha's position as reasonable.

Tillerson, an ex-CEO of oil giant ExxonMobil with strong ties to the region, visited Doha in July, where he signed an agreement on fighting terror financing.

Saudi Arabia and its allies the UAE, Bahrain and Egypt cut diplomatic ties and imposed sanctions on Doha in June, accusing it of backing extremist groups and of ties to Iran, in the region's worst diplomatic crisis in years.

Qatar has categorically denied the allegations.

The foreign ministers of four Arab states boycotting Qatar said on Sunday they would make no compromises in their demand that Doha change its policies.

The foreign ministers of the Saudi-led bloc who met in the Bahraini capital on Sunday, said they were open to talks with Qatar on condition it "stops its support and financing of terrorism".

A defiant Qatar has rejected the list of 13 demands from the coalition, which included shutting broadcaster Al Jazeera and the London-based The New Arab, downgrading diplomatic ties with Iran and closing a Turkish military base.

Qatar has stressed that lifting the blockade is a non-negotiable condition which the four countries besieging the emirate must adhere to before starting talks.