Secretary of State John KerryJohn Forbes KerryLet's not play Charlie Brown to Iran's Lucy The Memo: Democrats struggle to find the strongest swing-state candidate 2020 caucuses pose biggest challenge yet for Iowa's top pollster MORE sees signs that Russia is making "constructive choices" to ease tensions with Ukraine after the value of Moscow's currency, the ruble, collapsed.


"There are signs of constructive choices," Kerry said at a press conference in London on Tuesday. "That can only be helpful, hopefully."

Kerry cited signs of "calm" in eastern Ukraine and the "withdrawal of certain people."

The U.S. and European Union have for months pressed Russia over its support for separatists in Ukraine and its annexation of the Crimean peninsula, bringing sanctions against Moscow.

As the value of the ruble plummets, triggering major economic problems in Russia, Kerry pointed to the effect of the sanctions and the choices of Russian President Vladimir Putin. 

"There are a lot of combined factors, but the sanctions were clearly intended to invite President Putin to make a different set of choices," Kerry said. "Now these sanctions could have been lifted months ago. These sanctions could be lifted in a matter of weeks, days, depending on the choices of President Putin."

He said factors like the fall in oil prices also contributed to Russia's economic problems, but that the sanctions are key. 

"It goes without saying that the purpose of the Europeans, U.S. et al with respect to sanctions was to make it clear to Russia, to President Putin, that there are costs attached to the unilateral annexation of Crimea and the continued support for separatists in Ukraine," Kerry said.

The Russian central bank tried to stabilize the currency by spiking its interest rate by 6.5 percentage points in the middle of the night, but the ruble's value has not recovered.

Kerry said the effort is focused on Russian leaders, but there will be side effects on the Russian people.

"We do not want the people of Russia to be hurt here," he said. "But yes, collaterally of course, they are caught up in the choices that their government makes."