Russia has tested an "invincible" nuclear cruise missile that cannot be intercepted by enemy measures, claimed the country's president Vladimir Putin.
The head of state said the move is part of a new range of powerful nuclear and non- nuclear weapons it will build that will "reach anywhere in the world".
Putin added that Russia had also developed a high-speed underwater nuclear drone that can target both aircraft carriers and coastal facilities.
The leader made the revelations during his annual State of the Nation address on Thursday (1 March), ahead of elections for his fourth term as president, which he is expected to win on 18 March.
Putin has been in power since 2000, either as president or prime minister. If he wins the March poll he will be eligible to serve until 2024.
During a two-hour televised speech, Putin said the Russian army had first tested the new generation cruise missile last autumn.
He added the weapon was "a low-flying, difficult-to-spot cruise missile with a nuclear payload with a practically unlimited range and an unpredictable flight path, which can bypass lines of interception and is invincible in the face of all existing and future systems of both missile defence and air defence."
The Russian leader added the missile could not be stopped by US shields in place in Europe and Asia.
Putin, talking before a joint sitting of both houses of parliament, asked Russians watching on TV to write in and suggest names for the two new systems.
The president also said that Russia has tested a new heavy intercontinental ballistic missile, called Sarmat, which has a greater range and carries more warheads than its predecessor.
Putin said the development of the new weapons was in response to the US withdrawing from a Cold War-era treaty that banned missile defences and Washington's moves to boost its missile defence systems.