Gavin Williamson dubbed relations with Moscow “exceptionally chilly” after the poisoning of Russian former double agent Sergei Skripal and daughter Yulia, who remain in hospital along with a British policeman who went to their aid.
On Wednesday Theresa May announced the UK was expelling 23 Russian fake “diplomats” and taking other steps including a World Cup boycott by British officials and royals.
Mr Williamson said during a visit to Bristol: “We will look at how Russia responds to what we have done. It is absolutely atrocious and outrageous what Russia did in Salisbury.
“We have responded to that. Frankly, Russia should go away and should shut up. But if they do respond to the action we have taken, we’ll consider it carefully.”
Despite his trademark colourful language, he said the UK should not “rush” into any drastic measures against Vladimir Putin’s government.
He said: “We’ve have to be very careful in terms of the actions we take.
“They’ve got to be thoughtful and calibrated and ultimately they’ve got to have an effect against Russia… on those people at the top of the Russian regime that have decided to do this nation harm and to act in such an irresponsible and dangerous manner.”
However the Defence Secretary, who has been lobbying for more money for the UK military, also claimed cuts made in 2010 were based on a “naive” assessment that nation states were no longer a source of threats to the UK.
He said: “The whole field of warfare and conflict is changing. You are seeing them (Russia) operating in different ways.
“They are not holding back. You see what they are doing in Syria, what they are doing in Ukraine.
“They are effectively invading independent nation states and not caring about international reactions.
“We have got to open our eyes to the fact that people are willing to do so much more than they ever did in the past and we have got to be ready for those threats.”
Asked if the UK and Russia were entering a new Cold War, he said: “Let’s face it, relations ain’t good, are they?
“Russia has in my view made a deliberate political decision in terms of attacking Britain. It’s often described as a ‘cool war’ that we are entering. I would say it is feeling exceptionally chilly at the moment.”
Slating Jeremy Corbyn’s “disappointing” response to the attack, he added that it was “time for the whole country to unite” behind the Prime Minister, “Britain standing together against this great threat”.
Russia’s foreign ministry, which denies any responsibility for the poisoning, said Mr Williamson’s remarks showed London had something to hide.
The ambitious young Defence Secretary has a track record of using strong rhetoric against Russia, recently claiming the country could kill “thousands and thousands and thousands” of people in Britain by attacking the UK’s infrastructure.