Author Douglas Murray says former US President Donald Trump said "Germany was too reliant on Russian gas and that it would be paying a price for this" at the UN four years ago.

"And the German diplomats … all laughed away and giggled away at Donald Trump," he told Sky News host Rita Panahi.

"Now, you may not think that Donald Trump is the world's finest purveyor of truth.

"But he was telling the truth on this occasion.

"He was saying something that was absolutely true and giving the Europeans a reality check that was long overdue."