The US secretary of state has urged Saudi Arabia and other Arab Gulf states to ease their blockade on Qatar, saying it is causing unintended humanitarian consequences and affecting the US-led fight against the Islamic State of Iraq and the Levant (ISIL, known as ISIS) group.

Rex Tillerson's statement comes five days after Saudi Arabia, Bahrain, the UAE and Egypt cut diplomatic ties and transport links with Qatar, closing, air land and sea borders over and sending the Gulf Cooperation Council (GCC) countries into their largest crisis in years. 

"We call on the Kingdom of Saudi Arabia, the United Arab Emirates, Bahrain and Egypt to ease the blockade on Qatar," Tillerson said on Friday. 

He said blockade had caused "unintended" consequences and was "hindering US military actions in the region and the campaign against ISIS", referring to ISIL. 

"Our expectation is that these countries will immediately take steps to de-escalate the situation and put forth a good faith effort to resolve their grievances they have with each other."

The three Arab Gulf countries and Egypt accuse Qatar of supporting armed groups and their regional rival, Iran. Qatar says the charges are baseless.

On Thursday, they tightened their squeeze on Doha by placing 59 people and a dozen organisations with links to Qatar on a joint "terror" blacklist.

Tillerson said the blockade was "impairing US and other international business activities in the region", and had also caused inadvertent humanitarian consequences.

"We're seeing shortages of food [in Qatar], families are being forcibly separated, and children pulled out of school - we believe these are unintended consequences, especially during this holy month of Ramadan, but they can be addressed immediately."

READ MORE: Five days on, five things to know about Qatar-Gulf rift

Tillerson said the United States supported efforts by the emir of Kuwait to mediate the crisis, and said "the elements of a solution are available".

More than 11,000 US and coalition forces are stationed at the Al Udeid Air Base in Qatar, from which more than 100 aircraft operate.

Tillerson also said that Qatar has a history of supporting groups across a wide political spectrum, including those that engage in violence, and that the emir of Qatar had made progress in halting financial support for "terrorism" but that he must do more.

Saudi Arabia, the UAE, Bahrain and Egypt have suspended all flights to and from Doha and closed off sea and air links to Qatar.

Saudi Arabia has also closed off Qatar's only land border.

Qatar's Foreign Minister Mohammed bin Abdulrahman Al Thani on Friday described the blockade as a violation of international law and sad there was an attempt to mobilise international opinion against Qatar.

"These procedures that were taken have clear violations of international law and international humanitarian law. They will not have a positive impact on the region but a negative one," he told a press conference during a visit to Germany.

In an interview with Al Jazeera on Thursday, the foreign minister said that the country would not bow to the pressure being applied by Saudi, the UAE and their allies to change its independent foreign policy - a move Qatar considers a violation of its sovereignty.

Source: Al Jazeera News