Russia has flown two supersonic strategic heavy bombers over the international waters of the Barents Sea in a display of military might on NATO's doorstep.

The footage was released by the Ministry of Defence of the Russian Federation on July 19.

The Russian MoD titled the video: ‘Two Tu-160 strategic missile carriers carry out scheduled flight over international waters of Barents Sea'.

The MoD said: ‘MiG-31 crews from Air Force and Air Defence Formation of the Northern Fleet have escorted the missile carriers for protection.

‘The flight had been lasting over 7 hours.

‘All flights of the airplanes of Russian Aerospace Forces are conducted in a strict compliance with airspace regulations.'

The footage came as Russian President Vladimir Putin landed in Tehran, where he held talks with Iranian leaders and Turkish President Recep Tayyip Erdogan.

Amid the visit, the National Iranian Oil Company and Russian energy giant Gazprom signed a memorandum of understanding worth around USD 40 billion.

US officials had earlier warned that the Islamic Republic was intending to supply Moscow with hundreds of drones for use in Ukraine.

While President Putin was in Tehran, Ukrainian President Volodymyr Zelenskyy dismissed both the head and deputy director of his country's spy agency.

He also sacked Ukraine's prosecutor general and several regional security heads following the emergence of more than 650 cases of alleged collusion or treason.

Meanwhile, Ukrainian first lady Olena Zelenska has been in Washington, where she has held talks with senior figures including US first lady Jill Biden.

She will address lawmakers on Capitol Hill today (July 20) in an apparent bid to secure Kyiv more military aid from the USA.

And Russian independent television channel TV Rain, which was taken off the air by the Russian authorities in early March, has resumed broadcasting from Latvia.

The Kremlin blocked the channel shortly after the invasion of Ukraine began because it had used the term ‘war' rather than ‘special military operation'.

Dissent from Russians has continued, with tennis star Daria Kasatkina calling for an end to the ‘war' in a recent interview with Russian blogger Vitya Kravchenko.

The 25-year-old Russian number one and world number 12 living in Dubai described the invasion as a ‘full-blown nightmare'.

She also took aim at Moscow's stance on homosexuality, asking: ‘If there is a choice, nobody would choose being gay, why make your life harder, especially in Russia?'

While being gay is not illegal in Russia, homophobia is commonplace and the spreading of ‘gay propaganda' among minors is prohibited.