U.S. Secretary of State John Kerry has urged Russia not to interfere in the upcoming presidential poll in Ukraine, warning that Moscow risks more targeted economic sanctions.
Speaking in London after a meeting with foreign ministers from allied European countries on May 15, Kerry said the message for Russia was: "Let Ukraine vote."
Kerry said he hoped that Russia would play a constructive role in Ukraine's May 25 presidential election.
But Kerry said he and his European counterparts had agreed that Russia would face "sectoral economic sanctions" if the Kremlin tries to disrupt Ukraine's presidential elections later this month.
Kerry did not give details about the potential sanctions, but warned, "If they have to go into effect, they will have an impact."
Earlier on May 15, a senior State Department official said the U.S. shared with its allies its strategy of using a "scalpel rather than a hammer" to target vulnerabilities in Russia's business, banking, mining, energy, defense, or other sectors.
The meeting on May 15 was held ahead of discussions about the Syrian crisis by U.S officials and their counterparts from 10 other nations.
Meanwhile, President Vladimir Putin said on May 15 that, starting in June, Russia will deliver gas to Ukraine only if it pays in advance.
The warning came in an open letter to European leaders released by the Kremlin.
Putin said the state-controlled Gazprom energy company has been forced to demand advance payments after Ukraine's debt reached $3.5 billion.
Putin also called on the European Union to "more actively engage" in finding ways to stabilize Ukraine's crisis-hit economy.
Putin first warned that Russia will demand that Ukraine pay in advance for Russian gas in a letter to European leaders last month.
State Department deputy spokeswoman Marie Harf criticized Putin's statement, saying the energy issues between Russia and Ukraine should be settled "through negotiations, not through unilateral action, not through threats."
Ukraine has said it could start paying off its debt if Moscow restored the lower gas price Kyiv was paying before pro-Russian President Viktor Yanukovych was ousted in February.
Gazprom more than doubled the price of gas for Ukraine after Yanukovych was ousted.
With reporting by Reuters and AP