Asked by reporters on a visit to the United States on Tuesday if the demands were non-negotiable, Jubeir said: "Yes".
"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," Jubeir, who was in Washington, DC, said.
The four Arab countries have not provided any evidence for their claim, while Qatar has repeatedly rejected the allegation.
After more than two weeks, the Saudi-led bloc issued a 13-point demand list late on Thursday in exchange for the end of the anti-Qatar measures and gave a 10-day deadline.
The demands included, among others, that Qatar shut down the Al Jazeera media network, close a Turkish military base and scale down ties with Iran.
Qatari officials immediately dismissed the demands.
"This list of demands confirms what Qatar has said from the beginning - the illegal blockade has nothing to do with combating terrorism. It is about limiting Qatar's sovereignty, and outsourcing our foreign policy," Sheikh Saif bin Ahmed Al Thani, director of the Qatari government's communications office, said in a statement on Friday.
Qatar also said it was reviewing the demands and was preparing an official response.
Rex Tillerson, the US state secretary, has urged a diplomatic solution, and the US has been pushing for a clear list of grievances that are "reasonable and actionable".
Commenting on the Saudi-led bloc's list, Tillerson on Sunday said some of the demands "will be very difficult for Qatar to meet". Nevertheless, he added that the list includes "significant areas which provide a basis for ongoing dialogue leading to a resolution".
Turkish President Recep Tayyip Erdogan has denounced the demands as being "against international law", while Sigmar Gabriel, Germany's foreign minister, has called them "very provocative".
Separately, Tillerson met Qatar's Foreign Minister Sheikh Mohammed bin Abdulrahman Al Thani at the US state department on Tuesday to discuss the Gulf crisis.
Underscoring the administration's mounting frustration over the Saudi-led bloc's role in the crisis, Heather Nauert, state department spokesperson, recently urged the parties to settle their differences.
Nauert also called into question whether Qatar's alleged support for "terrorism" was the true cause of the crisis, or whether there was an underlying political dispute.
Source: Al Jazeera and news agencies