He suggests the plane was blown up from inside, saying that the head of Russia's investigative committee had reported to him a few days ago.

The Kremlin says Russia and North Korea have not signed any agreements on military matters or on any other areas during Kim's visit.

The plant produces Russia's most modern fighter jets.

For the US and allies, the burgeoning friendship between Kim and Putin is a concern.

Navalny, President Vladimir Putin's fiercest domestic critic, is already serving sentences totalling 11-1/2 years on fraud and other charges that he says are also bogus.

Legislators also approve raising the maximum sentence for carrying out 'a terrorist act' to 20 years, from 15 years at present.

He says 'everything is transparent' in their military-technical interaction.

While Washington plays down concerns about Putin's announcement, Nato says his non-proliferation pledge and description of US weapons deployment overseas are way off the mark.

Putin says the move to deploy tactical nuclear weapons to Belarus is 'nothing unusual'.

Dmitry Medvedev, who served as president between 2008 and 2012, has made increasingly hawkish speeches since Putin sent troops to Ukraine, repeatedly issuing nuclear threats.

Putin's surprise visit to Crimea was his first to the peninsula since he sent troops to Ukraine on Feb 24 last year, apart from when he drove across the bridge linking the territory to mainland Russia last December.

The arrest warrant for Putin, a sitting head of state of a UN Security Council member, is an unprecedented step for the ICC.