Russian President Vladimir Putin on Saturday offered to upgrade Belarus’ warplanes to make them capable of carrying nuclear weapons, amid soaring tensions with the West over Ukraine. “Many Su-25 (aircrafts) are in service with the Belarusian military. They could be upgraded in an appropriate way. This modernisation should be carried out in aircraft factories in Russia and the training of personnel should start in accordance with this,” Putin said after Belarusian President Alexander Lukashenko asked him to “adapt” the planes in a televised interview.