The $15 billion in loans and a $12 billion discount on natural gas prices "will not address the concerns of those who have gathered in public protest across Ukraine," White House spokesman Jay Carney told reporters in Washington.
"We urge the Ukrainian government to listen to its people and to find a way to restore a path to the peaceful, just, democratic and economically prosperous European future to which Ukrainian citizens aspire," Carney added.
Demonstrators in Kiev's central Independence Square, as well as Ukraine's opposition leaders, expressed anger at the news of the deal between Russian President Vladimir Putin and Ukrainian President Viktor Yanukovych in Moscow Tuesday.
Yanukovych "has given up Ukraine's national interests, given up independence and prospects for a better life for every Ukrainian," opposition leader and former World Boxing Council heavyweight champion Vitali Klitschko told tens of thousands of Independence Square protesters in remarks quoted by the Wall Street Journal.
Klitschko told the encamped protesters he suspected Yanukovych gave up Ukrainian strategic assets in return for Russian help.
The lawmaker, known as Dr. Ironfist when he boxed, called for early presidential elections and vowed to meet Yanukovych "in the ring," the BBC reported.
In Moscow, Yanukovych said Ukraine's deep economic ties to Russia made it "impossible for us to act in any other way" than to work out the deal he and Putin announced.
"There is no alternative to this," Yanukovych said.
The deal calls for Russia to buy $15 billion in Eurobonds Ukraine will issue and to sell Ukraine critical gas supplies from Russian state giant OAO Gazprom -- the world's largest natural gas extractor -- at $268.50 per 1,000 cubic meters through 2019.
Ukraine currently pays between $395 and $410. Most of Western Europe pays about $380 for Russian gas.
The deal saves Ukraine $2 billion a year, the New York Times said.
Putin, for his part, told Yanukovych, "Ukraine, without doubt, is our strategic partner and ally."
Moscow and Kiev said the leaders did not discuss the possibility of Ukraine joining Russia's nearly 4-year-old economic alliance of former Soviet states, known as the Customs Union, modeled after the European Union.
But Ukrainian opposition leaders said they suspected there were secret assurances given, or at least secret promises Ukraine would not sign any EU agreement, in exchange for the deal, the Financial Times reported.
Yanukovych has insisted he would move Ukraine -- a France-size former Soviet republic of 46 million -- toward European cooperation, even after halting plans to sign a cooperative framework for political, trade, social, cultural and security links, along with a free-trade deal, with the EU Nov. 21 -- a move that prompted the wave of demonstrations and civil unrest in Ukraine.
Yanukovych didn't address that issue Tuesday.