Putin spoke about this in a documentary about the occupation of the peninsula called Crimea: The Way Home, shown on Russia 1 TV channel, Censor.NET reports.
"On the first phase of the work I immediately had to orient our armed forces properly. Not only to orient, but to give direct orders over the possible behavior of Russia and our armed forces in any scenario," Putin said.
Answering the question about whether Russia was ready to alert nuclear forces if annexation of Crimea did not go well, Russian president said: "We were ready to do it."
Putin also said that Bastion missile complexes were deployed in the Crimea so that they could be seen from space.