Video report by Greg Hoare
Scotland's First Minister has become the first senior UK party leader to say that NATO should not rule out imposing a no fly zone over Ukraine.
Nicola Sturgeon said she shared concerns it could risk "direct military confrontation" between the nuclear powers of Russia and the west.
However, the First Minister argued "the west has to keep its mind open to every way in which Ukraine can be helped," and said the only thing nuclear weapons seemed to be deterring so far was "proper and direct" help for Ukraine.
The President of Ukraine has repeatedly called for NATO to introduce a no fly zone.
So far, western nations have ruled that out, warning enforcing it by shooting down Russian jets would lead to direct military confrontation between nuclear powers.