Ukraine's top security official Oleksiy Danilov said on Wednesday that Ukraine would impose a state of emergency on all of its territory, apart from the Donetsk and Luhansk regions where it has been in place since 2014.
He said that the emergency state would last 30 days and could be extended for another 30 days.
Pro-Russian separatists have controlled parts of Donetsk and Luhansk since 2014. Russia recognised them as independent states and approved use of its troops abroad this week.
Danilov also said that Ukraine's President Volodymyr Zelenskiy had not discussed the development of nuclear weapons, something Vladimir Putin has said posed a strategic threat for Russia.
(Reporting by Pavel Polityuk and Maria Tsvetkova; Editing by Alex Richardson)