Ukrainian President Volodymyr Zelensky addressing Ukrainian people during a broadcast speech.
"I explained it to all the negotiating groups: when you speak of all these changes (in a future accord) and they can be historic... we will come back to a referendum," Zelensky told Suspilne, an internet news site.
"The people will have to weigh in on certain kinds of compromise," Zelensky said, adding that what the compromises cover is part of the talks with Russia.
Zelensky spoke at length about the key question of whether Ukraine should never join NATO, as he recently conceded.
"We have all already understood it," Zelensky said, explaining that Ukraine will not be admitted to NATO because its member states "is afraid of Russia."
"That's all. And we have to calm down and say: 'Ok (we need) other security guarantees'," he said.
"There are NATO countries that want to provide security guarantees... who are ready to do what the alliance would do if we were members," the Ukrainian leader said.
"And I think this is a normal compromise," he said.
Moscow insists on a guarantee that Ukraine never is admitted to NATO, an organization created to protect Europe from the threat of the Soviet Union at the start of the Cold War.
Since the collapse of the Soviet Union, NATO has expanded to include countries on Russia's borders.