Qatar has welcomed a statement by the United States questioning the motives behind a series of anti-Qatar measures imposed this month by several Arab countries, according to a report published in state media.

Ahmed bin Saeed Al-Rumaihi, spokesman for Qatar's foreign ministry, expressed Doha's "welcome" on Wednesday, a day after the US state department said it was "mystified" that Saudi Arabia, the United Arab Emirates (UAE) and their allies had not released their claimed grievances about Qatar.

US 'mystified' over Gulf states' position towards Qatar

"At this point, we are left with one simple question: Were the actions really about their concerns regarding Qatar's alleged support for terrorism or were they about the long-simmering grievances between and among the GCC countries," Heather Nauert, spokesperson for the state department said on Tuesday, referring to the Gulf Cooperation Council.

Rumaihi on Wednesday reaffirmed "Qatar's strategic stance that supports solving the crisis by civilised dialogue", Qatar News Agency reported.

Saudi Arabia, the UAE, Bahrain and Egypt severed diplomatic ties and cut off sea and air links with Qatar on June 5, accusing it of supporting "terrorism" - a charge Doha strongly denies.

They ordered Qatari nationals to leave their countries, and also urged their citizens to return to their respective nations, disrupting the lives of thousands in the region and restricting their freedom of movement.

Sanctions also disrupted food and other imports into Qatar.

The UAE said this week the sanctions could last for years unless Doha accepted demands that the Arab powers plan to reveal in the coming days.

Qatar's Foreign Minister Mohammed bin Abdulrahman Al Thani said Doha would not negotiate with its neighbours to resolve the dispute unless they first lift the trade and travel restrictions.

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Qatar hosts the largest US military airbase in the Middle East, Al-Udeid, where more than 11,000 US and coalition forces are deployed or assigned and from which more than 100 aircraft operate.

Over the past two weeks, US President Donald Trump has taken a tougher stance against Qatar, while the State Department and the Pentagon had previously sought to remain neutral in the Gulf crisis.

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In remarks made on June 9, Trump said that "the nation of Qatar has historically been a funder of terrorism at a very high level", without, however, providing any evidence.

Al Jazeera's James Bays, reporting from Washington, DC, said that the state department's statement on Tuesday marked a change in US policy.

"Two weeks into the Gulf crisis, the state department is effectively changing sides, criticising those blockading Qatar," he said.

Bays said that the statement was "almost certainly cleared in advance" with the Pentagon and with the White House.

"But with this administration, you have to ask one question: is the president himself on board with the new policy?" he added.

"It also seems highly likely some of those countries who supported the blockade will now be lobbying President Trump to overturn this new position."

Qatar's foreign minister is expected to travel to Washington next week to hold talks about the ongoing crisis.

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Source: Al Jazeera and news agencies