Obama condemns Russian 'aggression' in Ukraine

US President Barack Obama has condemned Russian "aggression" in Ukraine.

Speaking in Warsaw to mark 25 years since the fall of communism in Poland, he hailed Polish democracy as a beacon for neighbouring Ukraine.
"How can we allow the dark tactics of the 20th Century to define the 21st?" he said.
Earlier Mr Obama met Ukraine President-elect Petro Poroshenko, and pledged support for plans to restore peace to the country.
Mr Obama called Mr Poroshenko a "wise selection" to lead Ukraine, and said the nation could become a vibrant, thriving democracy if the world community stood behind it.

Mr Obama said Poland's experience of democracy was a beacon for Ukraine

Mr Obama said Poland and America stood together

Leaders from across Central and Eastern Europe came to the event

Earlier Mr Obama met Mr Poroshenko, and called him a "wise selection" for leader of Ukraine

Mr Poroshenko, a billionaire sweet manufacturer, was elected in May and will be inaugurated as Ukraine's president on Saturday.
Mr Obama has said he will offer US support as Kiev tries to settle a gas bill with Russian supplier Gazprom, which has threatened to cut supply.
Ukraine's struggling economy has been in recession since 2012.
During a press conference after meeting Mr Poroshenko, Mr Obama also said the US would help train the Ukrainian law enforcement agencies and military, and provide equipment like night-vision goggles.
Symbolism The BBC's Adam Easton in Warsaw says Mr Obama chose to come to Poland for its symbolic value.
In his speech, the US president said that Poland's long struggle against occupation and tyranny was mirrored in the plight of Ukraine today.
"We will not accept Russia's occupation of Crimea or its violations of Ukraine's sovereignty," Mr Obama said.
"As we've been reminded by Russia's aggression in Ukraine, our free nations cannot be complacent in pursuit of the vision we share - a Europe that is whole and free and at peace."
Meanwhile, on the ground in Ukraine, separatist rebels have taken two military bases in the eastern region of Luhansk as fighting continues near the rebel-held town of Sloviansk.

Mr Obama's next stop is the G7 in Brussels, where activists are already waiting for him

European tour Mr Obama is on a three-country visit to Europe that takes him next to Brussels later on Wednesday for a meeting of the G7 major industrial nations.
It will be the world leaders' first gathering since Russia was removed from the G8 in protest over its annexation of Crimea in March.
Mr Obama is expected to meet Russian President Vladimir Putin in France on Friday, during 70th anniversary commemorations of the D-Day landings in Normandy.