MOSCOW (Reuters) - Russia on Thursday broadcast a series of videos showing the testing and operation of a new generation of nuclear and conventional weapons, days after Vladimir Putin and U.S. President Donald Trump discussed how to avoid an arms race.

President Putin announced an array of new nuclear weapons in March in one of his most bellicose speeches in years, saying they could hit almost any point in the world and evade a U.S.-built missile shield.

Both he and Trump, who held their first summit in Helsinki on Monday, have spoken of the need to avoid an arms race, and Putin has spoken of the urgent need to work to extend the new START strategic arms reduction treaty.

On Thursday, the Russian Defence Ministry aired Hollywood-style footage of many of the new weapons Putin unveiled in March being tested or in action.

It showed a Russian MiG-31 fighter jet taking off from an airfield carrying the new Kinjal hypersonic missile and then launching it while airborne.

MiG-31 jets which patrol the Caspian Sea have been armed with the Kinjal since April, the Interfax news agency reported.

The ministry also said it was preparing to conduct flight tests of a new nuclear-powered cruise missile, the Burevestnik or Storm Petrel.

The first footage of a live launch of the Avangard hypersonic missile, which Moscow says boasts "a glider maneuvering warhead," was also aired along with a clip of the heavy Sarmat intercontinental ballistic missile.

Putin's boasts about the new weapons have been greeted with scepticism in Washington, where officials have cast doubt on whether Russia has added any new capabilities to its nuclear arsenal beyond those already known to the U.S. military and intelligence agencies.

(Writing by Tom Balmforth; Editing by Andrew Osborn)