US President Barack Obama has warned Russia that any military intervention in Ukraine would lead to unspecified “costs.”
The US is consulting with its EU partners on potential costs.
Obama made an unexpected appearance in the White House briefing room to try to head off Russia after reports that armed men had taken over two airports in the Crimea region of southern Ukraine.
“We are now deeply concerned by reports of military movements taken by the Russian Federation inside of Ukraine,” he told reporters.
Obama said any violation of Ukraine’s sovereignty and territorial integrity would be “deeply destabilising.”
“The United States will stand with the international community in affirming that there will be costs for any military intervention in Ukraine,” he said.
German Foreign Minister Frank-Walter Steinmeier remained cautious about the situation in Ukraine.
“The latest signs still leave me worried, so we are keeping working to ensure a peaceful transition,” he said. “And this transition has to be achieved, first of all, by the Ukrainians themselves,” continued Steinmeier.
Euronews correspondent Stefan Grobe said: “Americans and Europeans are seeing the unfolding events in Ukraine with grave concern, especially the situation in Crimea. But the overall message is: There is no reason to panic – at least for now.”
Ukraine crisis – how it unfolded
24: Thousands protest in Kyiv over government move to shelve EU association agreement.
17: Ukraine secures a 11bn euro bailout from Russia.
19: Up to 200,000 gather in Kyiv to show opposition to newly-enacted anti-protest laws. Clashes between police and protesters.
20: Clashes continue into second day.
22: Kyiv Post reports five killed and 300 injured as clashes intensify.
23: Truce announced which paves the way for arrested protestors to be released.
28: Prime Minister Mykola Azarov resigns. Nine of 11 anti-protests laws repealed after vote in parliament. Stand-off continues between police and protesters in Kyiv.
18: 20,000 protestors march to parliament with MPs set to debate a possible new constitution. At least 17 people, including seven policeman, are killed as fresh clashes erupt.
19: Truce agreed.
20: Truce breaks down, fresh clashes see 48-hour death toll rise to at least 77.
21: Peace deal signed, with talk of early elections. Violence spreads to western Ukraine.
22: Protesters freely take control of presidential buildings amid reports Yanukovych has fled. Parliament votes to remove him with fresh elections set for May. Yanukovych appears on TV and denounces a “coup dêtat”. Opposition leader Tymoshenko released from jail.
23: Tymoshenko ally becomes acting president, saying European integration is a priority
25: Parliament votes for ousted Yanukovych to be tried at International Criminal Court.
26: Interim government moves to disband Ukraine’s riot police force as leaks lift the lid on the high-living of ousted president Yanukovych
27: Reports emerge suggesting Yanukovych is now in Russia as parliament appoints new pro-EU government. It comes amid fears of separatism after pro-Russian gunmen takeover government building in Crimea.
28: Yanukovych, speaking at a press conference, vows to fight for Ukraine, calls new government illegitimate and denies ordering police to fire on protesters. It comes as gunmen seize airports in Crimea.