Vladimir Putin has accused the United States of violating the nuclear balance and warned against a “Third World War” during a television call-in show.

Responding to a worried viewer who asked if such a war would occur, Mr Putin called for negotiations in an attempt to return to the strategic parity the United States and Soviet Union had during the Cold War.

Quoting Albert Einstein’s aphorism that “World War IV will be fought with sticks and stones”, he said the US exit from the Soviet-era anti-ballistic missile treaty in 2002 had disrupted the balance.

“The fear of mutually assured destruction has always restrained and forced military powers to respect each other,” he said. “The exit of the United States from the missile defence treaty was an attempt to ruin this parity, but our efforts in the development of new weapons will preserve this parity.”

In March, the Russian president announced an array of “invincible” new nuclear weapons including an underwater drone and glider warhead that he claimed could overcome US missile defences.

US intelligence has said a nuclear-powered hypersonic missile whose range Mr Putin said was “unlimited” in fact crashed after 22 missiles in a test.

About 80 lucky Russians were able to submit questions directly to the head of state in the annual live

television event.

The carefully stage-managed programme was a chance for Mr Putin to show off his grasp of issues that worry Russians and score points by solving them, or at least ordering officials to take care of them.

Almost two million Russians had submitted questions before the four-hour show began.

A televised tongue-lashing from Mr Putin can typically kick off activity amid even the most intractable bureaucracy. In past years, regional officials have begun scrambling to address problems before the call-in show even ends, worried for their security of their jobs.

The initial question came in the form of a video shot by driver Alexei Karavayev in the cab of his lorry in St Petersburg and touched on what hosts had said would be one of the main topics of the show.

“Vladimir Vladimirovich, please tell us, how much higher will petrol prices go? Forty-five roubles for a litre of diesel, it’s impossible!” he said.

“I agree. What’s going on is

impermissible, it’s not right, but we need to admit it’s not the result of soft regulation in the energy sphere,” Mr Putin responded, before launching into an explanation of the measures that the government had

been taking to cut prices.

Another early topic was the World Cup, which kicks off in Russia nexton Thursday. A planned question from well-known football trainer Valery Gazzaev invoked several Orthodox saints and repeatedly wished Mr Putin good health.

The president spoke about the legacy of the tournament, warning that the stadiums built in 11 cities shouldn’t become white elephants but rather help to “develop a new generation of football players”.

In a first this year, the governors of Russia’s 85 regions were on live feeds during the call-in show, ready to answer for whatever problem might come up in their patch.

The tendency to blame regional officials stretches back years and even gave rise to an old Russian saying, “The situation is worse than a governor’s”.

Responding to a mother of three children who asked why she had been waiting eight years for free land promised to large families, Mr Putin called up the governor of her region, who promised to take care of the problem.

“We should strive so that every family had at least three children. We should facilitate families like yours,” Mr Putin said, in a reference to the concern over population decline in the past two decades.

Russia’s highly centralised political system means Mr Putin’s words carry great weight.

He previously appointed governors for approval by regional parliaments, and the Kremlin still enjoys influence over who the ruling party puts forward for election.