Russian enterprises having worked with plants in Ukraine's eastern Donetsk region had already been facing problems this year since Ukraine barred deliveries of military products made to Russian orders, Sobko said.
"The fact that he [Poroshenko] has legally fixed it is absolutely not news for us," he noted, adding that Russia was actively working on import substitution.
"We have additional cares," Sobko said. "But no matter. If there are such changes in the world, we will survive."
Even new law was not required to advance import substitution, Sobko said. "We have everything. It can be settled in the working process and no special law is needed. We must see which enterprises will take on additional work to make the products formerly ordered from Ukraine."
President Petro Poroshenko has signed a decree banning export of military and dual-use items to Russia, thus enforcing the National Security and Defense Council's August 27 decision to stop sending to Russia military and other items that may be used by armed forces - exemption granted to equipment used for research and peaceful purposes as part of international space projects.
Poroshenko's move lags a week behind plans already announced by Russia's Industry and Trade Ministry that domestically manufactured defence equipment will now replace military items previously supplied by Ukraine.
Russian orders placed with Ukraine by April came to around $15 billion, 8.2% of Ukraine's gross domestic product.
Military experts say ceased co-operation hits 79 Ukrainian and 859 Russian defence enterprises. Ukraine has supplied many military engine components. These included parts for Voevoda R-36M2 ballistic missiles (known by NATO as Satan), engines for helicopters, aircraft and rockets, turbine units for ships and guidance systems for tanks, aircraft and anti-aircraft missile systems.