The new sanctions would include "national measures to freeze the financial assets of Russian figures", it said in a statement, after President Emmanuel Macron chaired a defence meeting.

France would, with European partners, also move towards excluding Russia from the SWIFT bank messaging system.

There would also be "measures to counter propaganda by Russian influencers and media on European soil", it said, without providing further details.

SWIFT's messaging system allows banks to communicate rapidly and securely about transactions, and cutting Russia off would cripple its ability to trade with most of the world.

But that could complicate remaining trade with Europe, including natural gas imports vital to the continent's energy supply as well as oil shipments.

Macron on Saturday also spoke to the leader of Belarus, Alexander Lukashenko, who allowed Russian troops to use Belarusian territory to invade Ukraine from the north.

He asked him "to demand as soon as possible the withdrawal of Russian troops from his soil," and urged him to cooperate with the international community to allow humanitarian aid to the Ukrainian people.

- 9,500 soldiers on alert -

A French military source on Saturday announced it would mobilise or put on alert more than 9,500 soldiers by next weekend.

More than 1,500 French personnel will be "directly involved" in NATO's reinforcement missions in eastern Europe, a military source told AFP.

Some 500 soldiers will be deployed to Romania and 100 more will join the 300 French troops already in Estonia, which will also receive four Mirage 2000-5 fighter jets, the source added.

The source said France has mobilised 600 soldiers to take part in flights above Poland and that France has sent two aerial missions there per day since Russia's invasion of Ukraine on Thursday.

A further 8,000 French troops are on alert within NATO's rapid reaction force, which France is commanding in 2022, the source added.

NATO deployed multinational battalions to Poland and the Baltic states -- Latvia, Estonia and Lithuania -- following Russia's annexation of Ukraine's Crimea peninsula in 2014.

France's chief of the defence staff on Friday said NATO would send a "message of strategic solidarity" and "a real signal of firmness and clarity to Russia".