Ahead of a visit Thursday to Belgrade, Russian President Vladimir Putin has blamed Western countries for "destabilising" the Balkans, returning an accusation often lobbed in his direction.

Vladimir Putin was one of around 100 guests at Karin Kneissl's wedding to a businessman in southeastern Austria on Saturday.

Donald Trump said not a single critical word about Russia on any of the issues that have brought relations between the Washington and Moscow to a post-Cold War low.

Hours before he was due to sit down for his first ever summit with Vladimir Putin, US President Donald Trump blamed "US foolishness" for bad relations between Washington and Moscow, while the Kremlin said it expected a tough meeting.

A Russian soccer commentator said he will no longer do World Cup matches for Russia's biggest state-run broadcaster, four days after breaking a taboo by naming President Vladimir Putin's biggest critic live on air.

The Russian leader said that there is "nothing that inspires confidence" in the international investigation and that "several versions" of what happened exist.

Russia's Vladimir Putin watched advanced jets carrying a hypersonic missile he has touted as invincible scream over Red Square on Wednesday, days after the start of his fourth presidential term.

Vladimir Putin, in power since 2000, wants Russia to reduce its dependence on imported goods and technology, a drive that has gathered pace since Russia was hit by Western sanctions.

Russian opposition leader Alexei Navalny and around 1,600 anti-Kremlin activists were detained by police on Saturday during street protests against Vladimir Putin ahead of his inauguration for a fourth term as president.

Critics of Vladimir Putin took to the streets of Russia on Saturday ahead of his inauguration for a fourth presidential term to register their opposition to what they say is his autocratic Tsar-like rule.

In an usually strong turnout, at least 8,000 people including top opposition leader Alexei Navalny turned up in the centre of the Russian capital, many holding placards and shooting paper airplanes.

Turkish President Recep Tayyip Erdogan and Russian counterpart Vladimir Putin on Tuesday launched the construction of Turkey's first nuclear power plant in the Mediterranean Mersin region.