Ukraine Crisis

Earlier on Wednesday, the websites of several Ukrainian banks and government departments became inaccessible.

At the same time a new "wiper" attack, which destroys data on infected machines, was discovered being used against Ukrainian organisations.

The incident represents the third wave of attacks against Ukraine this year, and the most sophisticated to date.

The latest attack began on Wednesday afternoon when internet connectivity company NetBlocks tweeted about the outages, saying "the incident appears consistent with recent DDoS attacks".

The Russian president's comments came as the military said that some troops were withdrawing from the border near Ukraine - the first sign from Moscow of a possible de-escalation of tensions.

However Western leaders say there is no evidence of the withdrawal yet.

Russia's sudden military build-up prompted fears it would invade Ukraine.

Mr Putin has always denied he is planning an incursion, but tensions have been rising since November, when Russian troops started massing near the border with Ukraine.