Adel al-Jubeir, Saudi foreign minister, said on Twitter on Saturday that "demands on Qatar to stop funding terrorism are non-negotiable".
"Restrictions on Qatar show zero tolerance for terrorism," Jubeir said, claiming that Doha had failed to keep previous pledges of stopping "funding terrorism and interfering in other countries' affairs". Qatar denies all allegations.
Jubeir made a similar statement last week in Washington, DC, when asked by reporters if the 13 point list of demands that are widely denounced as "unrealistic" was non-negotiable.
"We made our point, we took our steps and it's up to the Qataris to amend their behaviour and once they do, things will be worked out, but if they don't they will remain isolated," he said on Tuesday.
The demands issued with a 10-day deadline last week include downgrading ties with Iran, shutting down Al Jazeera Media Network and Turkish military base in Doha.
The exact time of the deadline was not discussed but it is expected to become void on Monday.
The four Arab countries have not provided any evidence for their claim.
On Friday, Qatar's Foreign Minister Mohammed bin Abdulrahman Al Thani asked members of UN's Security Council to urge a Saudi-led bloc of states to lift their blockade on the Gulf country.
Source: News agencies