The Defense Secretary insisted that Britain will not become internationally isolated by its tough stance towards the Russian President, as he called on Mr. Trump not to treat Russia as an "equal partner", The Telegraph reported.
Vladimir Putin was one of the first world leaders to congratulate Mr. Trump on his victory and the pair vowed to establish a new relationship between the U.S. and Russia based on "mutual respect".
It came after Mr. Trump expressed admiration for the Russian president during his campaign for the White House.
However, Mr. Fallon suggested Mr. Trump might change his tune when he becomes president.
Read alsoTrump says No to another "reset" with Russia - mediaSpeaking to Radio 4's Today program, he said: "I don't agree with that and I think you have to distinguish between the campaign rhetoric of president-elect Trump and what he does in practice."
"In practice every American administration has always stood up to Russia. We're not suggesting you shouldn't talk to Russia but what you can't do is treat Russia as business as usual, as any kind of equal partner."
"Russia is clearly breaking the international rules by what it did in Crimea and Ukraine and that can never be forgotten."
He added that the latest deployment of 150 British troops to Poland was part of an effort to face down Putin's attempt to "test" NATO.
