Kuwait is trying to mediate a regional crisis in which Arab countries have cut diplomatic ties with Qatar and moved to isolate the energy-rich, travel-hub nation from the outside world, Qatar's foreign minister said.
Yemen's internationally recognised government also cut ties with Qatar, accusing it of working with its enemies in the Iran-aligned Houthi movement, state news agency Saba reported.
Sanctions include shutting down transport links, including closing borders, airspace and maritime territories, which led to fears of supply shortages.
In an interview on Monday with Al Jazeera, Foreign Minister Sheikh Mohammed bin Abdulrahman Al Thani said Kuwait's ruler, Sheikh Sabah Al Ahmad Al Jaber Al Sabah, had asked Sheikh Tamim bin Hamad Al Thani, Qatar's ruling emir, to hold off on giving a speech about the crisis late on Tuesday night.
"He received a call from the emir of Kuwait asking him to postpone it in order to give time to solve the crisis," Sheikh Mohammed said.
Sheikh Sabah called on Qatar's ruler to focus on easing tension and advised against making decisions that could escalate the situation, Kuwait state news agency Kuna said.
Still, the Qatari foreign minister struck a defiant tone, saying his nation rejected those trying to impose their will or intervene in its internal affairs.
Kuwait, Oman 'fear escalation'
Analyst Giorgio Cafiero of Gulf State Analytics, a geopolitical risk consultancy based in Washington, DC, told Al Jazeera: "I think the Kuwaitis as well as Omanis ... fear the prospects of these tensions escalating in ways which could undermine the interest of all six members of the GCC.
"There are many analysts who believe that a potential break-up of the GCC has to be considered right now."
He added that if tension escalates, some have warned of a "military confrontation".
"If these countries fail to resolve their issues and such tensions reaches new heights, we have to be very open to the possibility of these six Arab countries no longer being able to unite under the banner of one council," said Cafiero.
The dispute between Qatar and the Arab countries escalated after a recent hack of Qatar's state-run news agency. It has spiralled since.
As it cut ties on Monday, Saudi Arabia charged that Qatar was embracing "various terrorist and sectarian groups aimed at destabilising the region," including the Muslim Brotherhood, al-Qaeda, the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) and armed groups supported by Iran in the kingdom's restive east.
Egypt's Foreign Ministry accused Qatar of taking an "antagonist approach" towards Cairo and said "all attempts to stop it from supporting terrorist groups failed".
Qatar denied the allegations, with a Foreign Ministry statement describing them as "baseless" on Monday.
The group issuing sanctions on Doha "is clearly the imposition of guardianship over Qatar, which is in itself a violation of its sovereignty, and is rejected outright," the statement said.
The move came just two weeks after US President Donald Trump visited Saudi Arabia and vowed to improve ties with both Riyadh and Cairo to combat terrorism and contain Iran.
US Secretary of State Rex Tillerson said the move was rooted in long-standing differences and urged the parties to resolve them.
"It is true that the current US administration is adopting to have a bit more Saudi position distant from Qatari position," Richard Weitz, a senior fellow and director of the Center for Political-Military Analysis at Hudson Institute, told Al Jazeera
"But I still think that the US military contacts can play a good role to help resolve perhaps some of the difference, since US military particular want an end to this dispute because of the difficulties to find a space and terrorism cooperation and so on."
The Gulf countries ordered their citizens out of Qatar and gave Qataris abroad 14 days to return home to their peninsular nation, whose only land border is with Saudi Arabia. The countries also said they would eject Qatar's diplomats.
The nations also said they planned to cut air and sea traffic. Trucks carrying food had begun lining up on the Saudi side of the border, apparently stranded. The Qatar Stock Exchange fell more than seven percent in trading Monday.
Qatar Airways, one of the region's major long-haul carriers, has suspended all flights to Saudi Arabia, the UAE, Egypt and Bahrain until further notice.
On its website, the carrier said the suspension of its flights would take effect Tuesday and customers are being offered a refund.
The route between Doha, Qatar and Dubai is popular among business travellers and both are major transit hubs for travellers between Asia and Europe.
Source: Al Jazeera and news agencies