Nato troops moving east to avert 'spillover' from Ukraine war

He declined to give details on which parts of the multinational force, which contains 5,000 ground troops with air and naval support, might be moved east or when the move would begin or be completed.

But Nato had also put hundreds of fighter planes and warships on high alert "from the Barents Sea to the Mediterranean," Stoltenberg added.

Nato already had US, British, German and other troops in Russia-deterrent battalions stationed in the Baltic and Black Sea regions years ago.

And it gave its military commanders greater freedom Thursday to move troops around the field, Stoltenberg said.

Speaking hours after Russian forces poured into Ukraine around dawn on Thursday, Stoltenberg said Nato's posture was meant to act as a deterrent against a potential spillover of the conflict.

He voiced compassion for Ukrainian people amid incoming reports of civilian casualties.

But he underlined that there was no present danger of a Nato-Russia confrontation. "There are no Nato troops in Ukraine," he said.

"As long as Russia knows that an attack on a Nato ally will trigger a response from the whole alliance they will not attack because we are the strongest alliance in history," Stoltenberg said. "That's the best way to prevent spillover from the tragedy, the heinous attack we see on Ukraine," he said.

Russia had "shut the door to a political solution", Stoltenberg said, when asked if any Nato leaders planned to talk to Moscow.

But Nato and Russian military commanders were in contact using "deconfliction channels" to prevent the risk of escalation, he explained.

Nuclear rhetoric

Earlier in the day, Russian president Vladimir Putin had warned Western countries not to interfere in the Ukraine conflict in what many saw as a threat to escalate to the level of nuclear weapons.

When asked by one journalist in Brussels on Thursday if that was how he saw it too, Stoltenberg declined to answer directly, instead indicating that the Russian nuclear posture was so not much an immediate concern but more a question for "our long-term relationship."

Nato countries were free to keep supplying weapons to Ukraine amid Putin's "aggressive rhetoric," Stoltenberg said. "It will be a national decision[s] in what way allies continue to provide support", he noted.

US president Joe Biden was expected to speak with fellow Nato leaders in a virtual summit Friday that would include two Nato-aligned countries, Finland and Sweden, which are not covered by its mutual defence treaty, Stoltenberg announced.

Those military talks are to follow an EU leaders' meeting in Brussels Thursday evening, when EU officials have pledged to come forward with far-reaching economic sanctions against Russia.

The Nato secretary general said Western intelligence had seen the invasion coming.

But it was struggling to keep up with the "full damage assessment" of Russia's actions, he said. The full extent of Putin's intentions by invading Ukraine could not be predicted, he added.

"We don't have all the answers today but there will be a new reality, a new Europe after the invasion that we saw today," Stoltenberg said.

Bosnia reinforcement

Nato moves aside, the EU also decided to send 500 extra peacekeeping soldiers to its Althea mission in Bosnia on Thursday.

They were going as a "precautionary measure" in case the Ukraine conflict "spread instability to Bosnia and Herzegovina", Althea said.

The reserve forces, from Austria, Bulgaria, Romania, and Slovakia were to arrive in the next two weeks, joining 600 Althea soldiers who were already in place under normal conditions.

Republika Srpska, the Russia-friendly Serb entity in Bosnia, began threatening last year to sever from federal institutions, ending a 1995 peace deal.