The Kremlin on Thursday said British Foreign Secretary Boris Johnson had made "disgusting" comments about President Vladimir Putin seeking to exploit Russia's World Cup in the way Adolf Hitler had used the 1936 Berlin Olympics.
"This is a completely disgusting statement. This is beneath the foreign minister of any country. Of course it is offensive and unacceptable," said presidential spokesman Dmitry Peskov.
The previous day, Johnson agreed with a fellow British MP who had suggested that "Putin is going to use it in the way Hitler used the 1936 Olympics", as a propaganda exercise.
"I think the comparison with 1936 is certainly right," the minister replied, envisaging Putin "glorying in this sporting event".
The comments came amid an escalating war of words between Russia and Britain over the poisoning of a Russian former double agent on British soil this month. Moscow denies involvement in the case.
Johnson also called for Russian guarantees over the safety of England fans at the World Cup.