U.S. Secretary of State John Kerry is in London for talks with Russian Foreign Minister Sergei Lavrov on the crisis in Ukraine. U.S. officials said they are “very concerned" over the Russian troop movements along the border with Ukraine, which they said "create an atmosphere of instability" ahead of Sunday's referendum on the fate of Crimea.
Secretary Kerry said he is in London to push Russian leaders toward what he calls a "more reasonable path" in Ukraine.
"The key will be to figure out whether or not President Putin is serious about looking for a way under international law to move this process forward," said Kerry.
With voters in Crimea preparing for a referendum Sunday that could see them joining the Russia Federation, Kerry said the United States and European Union are ready to respond.
"There will be a response of some kind to the referendum itself, and, in addition, if there is no sign of any capacity to move forward, and resolve this issue, there will be a very serious series of steps on Monday in Europe and here with respect to the options that are available to us," he said.
But Kerry pointed out that sanctions and hostility are not Washington's preferred outcome. Instead, he said, the Obama administration prefers a solution in which Russia joins in respecting international law.
U.S. and European leaders have said Sunday's referendum is unconstitutional. Russian officials retort that voters in Crimea have a right to self-determination following last month's collapse of the pro-Russian government in Kyiv.
American University professor Keith Darden says neither side is likely to see this referendum as a clear resolution one way or the other.
"It doesn't even give the population the option of remaining in the current status they have with respect to sovereign Ukraine. So it is actually a terribly formulated referendum," said Darden.
Ahead of his talks here with Foreign Minister Lavrov, Secretary Kerry will meet with British Foreign Minister William Hague and with Prime Minister David Cameron.