Russia's foreign minister Sergei Lavrov has warned that Ukraine's bid to join Nato could "derail" the peace process in the east of the country.
Ukraine's government wants to join the defence alliance but some sections of its population, including its Russian-speaking minority, are opposed.
“This is an obvious attempt to derail all efforts to initiate a dialogue aimed at providing national security," Lavrov is quoted as saying by a Russian news agency.
Were the Russians -as Barack Obama claims - weighed down by sanctions, or where the Ukrainians looking to cut their losses?
The new president of the European Council could be "very important" for David Cameron.