Four Arab states have sent Qatar a list of 13 demands it must meet if it wants them to lift their sanctions, news agencies report.
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 denies funding terrorism and fostering regional 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.
A murky business: analysis by Lyse Doucet, BBC chief international correspondent
This fight is a murky business in the region.
Money from official and private sources has flowed to armed groups from most Gulf states for years. In Syria’s war, it often amounted to sacks of cash dropped at hotels in Turkey. That is where accountability often ended as money moved across the border to messy battlefields.
Qatar repeatedly came under criticism in many capitals for allegedly backing the al Qaeda-linked Hayat Tahrir al-Sham, which was previously known as al-Nusra Front and is one of the most formidable jihadist groups battling President Bashar al-Assad’s forces. But other Gulf states, including Saudi Arabia, also fund hardline Islamist fighters.
According to the Associated Press news agency, which obtained a copy of the list, Qatar must also:
- Sever all ties with the Muslim Brotherhood, which is banned in other Arab states
- Refuse to naturalise citizens from the four countries and expel those currently on its territory, in what the countries describe as an effort to keep Qatar from meddling in their internal affairs
- Hand over all individuals who are wanted by the four countries for terrorism
- Stop funding any extremist entities that are designated as terrorist groups by the US
- Provide detailed information about opposition figures whom Qatar has funded, ostensibly in Saudi Arabia and the other nations
- Align itself politically, economically and otherwise with the Gulf Co-operation Council
- Stop funding other news outlets in addition to Al Jazeera, including Arabi21 and Middle East Eye
- Pay an unspecified sum in compensation
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.