Qatar has vowed to ride out the isolation imposed on it by fellow Arab states and said it would not compromise its sovereignty over foreign policy to resolve the region's biggest diplomatic crisis in years.
Gargash said the four Arab states seek a "political commitment to change course" by Qatar, including ending its support for the Brotherhood and Hamas.
"Despite these efforts, entities and individuals within Qatar continue to serve as a source of financial support for terrorist and violent extremist groups, particularly regional Al-Qaeda affiliates such as the Nusrah Front", the State Department said.
Saudi Arabia's closure of Qatar's only land border sparked fears of major price hikes and food shortages for its population of 2.7 million people, with long queues forming as some supermarkets began running out of stock.
Noting that the blockade is also impairing U.S. and other global business activities in the region, Tillerson said it has created a hardship on the people of Qatar, and the people whose livelihoods depend on commerce with the Gulf nation. "We truly believe that the involvement of the president and the USA will bring this crisis to an end".
"If there is any sensible argument or sensible accusation, we are ready to answer", Sheikh Mohammed said.
Arab states in row with Qatar laud Trump's supportive stance
Al-Jazeera's offices have been shut down by authorities in Saudi Arabia and Jordan. They accused it of supporting terrorism, a charge that Qatar denies.
File image of Qatar's foreign minister Sheikh Mohammed bin Abdulrahman al-Thani. "We need to have a close exchange of ideas with Turkey regarding these incidents", Zarif told reporters, before meeting with his Turkish counterpart and Erdoğan.
Turkey will send warplanes and warships to Qatar after an initial deployment of troops to a Turkish base there, the mass-circulation Hurriyet newspaper said on its website.
The fake article quoted Sheikh Tamim as calling Iran an "Islamic power" and saying Qatar's relations with Israel were "good" during a military ceremony. The Gulf sheikdoms had previously recalled their ambassadors from Qatar in 2014, over its support for the Muslim Brotherhood.
The Ashcroft firm was hired to do a compliance and regulatory view of Qatar's anti-money laundering and counterterrorist financing framework, Sullivan said in an email.
Sheikh Mohammed said Qatar was willing to discuss with its neighbours "anything related to the collective security of Gulf countries". Qatar "has to realize its interests are with us, not with another country that conspires against us, wants to dominate and divide us", Bahrain Foreign Minister Khalid bin Ahmad al-Khalifa told Asharq al-Awsat, a Saudi-owned newspaper.
Among the sanctioned parties are charities and fundraisers in Qatar that have acted for the benefit of Al-Qaeda for more than a decade.
In a sign of the economic damage from the dispute, Standard & Poor's downgraded Qatar's debt on Wednesday as the country's riyal currency fell to an 11-year low amid signs that portfolio investment funds were flowing out because of the rift.
Regional tensions, already high following the diplomatic dispute, ratcheted up further after militants attacked targets in Tehran on Wednesday, killing at least 12 people.