Four Arab states have sent Qatar a list of 13 demands it must meet if it wants them to lift their sanctions.
Saudi Arabia, Egypt, the United Arab Emirates and Bahrain are asking the Gulf state to shut down its broadcaster, Al Jazeera.
They are also asking Qatar to reduce ties with Iran and close a Turkish military base – all within 10 days.
Qatar, which sought to raise its profile in recent years, denies funding terrorism and fostering instability.
It has been subjected to more than two weeks of unprecedented diplomatic and economic sanctions, in the worst political crisis among Gulf countries in decades.
The list was announced after US Secretary of State Rex Tillerson urged Qatar’s neighbours to make their demands “reasonable and actionable”.
Correspondents say there has been frustration in Washington, which is seeking to resolve the dispute, over the time taken by the Saudis and others to formalise their demands.
There was no immediate response from Qatar but Foreign Minister Sheikh Mohammed bin Abdulrahman al-Thani said earlier that it would not negotiate until the punitive measures were lifted.
An unnamed official from one of the four countries told Reuters news agency that Qatar was also being asked to sever links with so-called Islamic State, al-Qaeda and Lebanese Shia militant group Hezbollah.
According to the document seen by AP, Qatar is being asked to shut down diplomatic posts in Iran, expel any members of Iran’s elite Revolutionary Guard and only conduct trade with Iran that complies with US sanctions.
The document specifies that both Al Jazeera and all of its affiliates must be shut down. Al Jazeera, which has an English-language branch, is one of the most widely watched Arabic satellite channels.
Gulf countries and Saudi Arabia’s close ally, Egypt, have long accused the broadcaster of providing a platform for Islamist movements and encouraging dissent – claims the broadcaster has denied.
Turkey has been supplying Qatar with food and other goods by air since the sanctions started, and dispatched its first ship carrying food this week, Reuters reports.
Turkish exports to the Gulf state have tripled from their normal levels to $32.5m in that period, Turkish Customs and Trade Minister Bulent Tufenkci said on Thursday.
However, Turkish Economy Minister Nihat Zeybekci was quoted as saying that it was not sustainable to maintain supplies through an air lift.
The Turkish military base in Qatar was set up under an agreement signed in 2017.