The Russian military announced massive drills of its strategic nuclear forces, a stark reminder of the country's nuclear might amid Western fears that Moscow might be preparing to invade Ukraine.
The Russian Defence Ministry has said that President Vladimir Putin will oversee exercises by Russia's nuclear forces involving the launch of ballistic and cruise missiles.
Kremlin spokesman Dmitry Peskov said on Friday the exercises were part of a regular training process and denied they signalled an escalation of the standoff.
Peskov said Putin's role was essential, and the president was likely to take part from a "situation centre".
The drills follow a huge series of manoeuvres by Russia's armed forces in the past four months that have included a buildup of troops — estimated by the West to number 150,000 or more — to the north, east and south of Ukraine.
Putin and other top officials frequently refer to the fact that Russia, together with the United States, is one of the world's leading nuclear powers.
Testing military readiness
The Defence Ministry said the drills would test the readiness of military command and control, combat crews, warships and strategic missile carriers, as well as the reliability of strategic nuclear and non-nuclear weapons.
They would involve Russia's Aerospace Forces, its Southern Military District, Strategic Missile Forces, Northern Fleet and the Black Sea Fleet.
Russia's strategic rocket forces number 50,000 personnel out of its overall active military forces of 900,000, the International Institute for Strategic Studies said this week in its annual Military Balance report.
It said their technology had been significantly upgraded over the past six years.
Abrams tanks for Poland
Meanwhile, US Defense Secretary Lloyd Austin announced on Friday the planned sale of 250 Abrams tanks to Poland, as Washington moves to strengthen the defences of a key eastern European ally amid a mounting threat of war between neighbouring Ukraine and Russia.
"This is the most modern version of the Abrams, and will provide Poland with a highly advanced tank capability," Austin told a news conference following talks in Warsaw, adding that the delivery timeframe was under discussion.
"It will also strengthen our interoperability with the Polish armed forces, boosting the credibility of our combined deterrence efforts and those of our other NATO Allies."