Donald Trump warned of 'big trouble' after the powerful MiG-31 warplanes spent 12 minutes violating Estonian airspace on Friday as they tested the country's defences.

The defensive alliance rushed to mobilise duty warplanes today to repel the Russian jets which violated its member's airspace.

Tallinn said that three Russian MiG-31 fighter jets violated the airspace of NATO member Estonia over the Gulf of Finland for 12 minutes on Friday.