"Whatever path Russia chooses, the United States and our allies will stand together in our defense of Ukraine," Sec. of State John Kerry said.
Russian Foreign Minister Sergei Lavrov slammed U.S. and EU sanctions over the Ukraine crisis Tuesday, saying they defied common sense.
The Europeans, unlike the Americans, are not hitting the head of Russia's state-owned oil company, Rosneft, with sanctions.
Shareholders have urged big oil firms like BP and Shell to control spending and give back more cash because of concerns over rising costs.
Russia's deputy foreign minister said that Moscow is prepared to respond to Western sanctions with a range of measures.
Across party lines and age groups, Americans want Russia to feel the heat.
The latest round of sanctions on Russia hits people close to Putin, but they won't make a dent in the world's sixth-largest economy.
The decision brings to 48 the number of people the EU has put under sanctions for, it argues, helping undermine Ukraine's territorial integrity.
MasterCard said it's suspending services to Russia's SMP bank and InvestCapitalbank, which were sanctioned on Monday by the U.S.
The new sanctions list includes seven Russian officials and 17 companies, from the financial, energy and infrastructure sectors.
Templeton Group's Mark Mobius said his emerging markets fund holds about $200 million in Ukrainian stocks and $500 million in Russian equities.
Ukraine has been trying to secure alternative supplies to those from Russia's Gazprom since Moscow annexed Crimea last month.
Two people from the Russian president's inner circle are among the seven whose U.S. assets have been frozen, in this third round of sanctions.
The heavyweight champion knocked out his opponent in the fifth round in Germany.
The European Union is also expected to add targets to its Russia sanctions list on Monday.
While Asian markets fretted about Ukraine and rising oil prices, markets in US and Europe are buoyed by M&A buzz.
Obama continues to seek unity - and stronger measures - vs. Moscow.
Global markets on alert, with the crisis in Ukraine to euro zone inflation and beyond.
Extraordinary footage catches an attack on a Ukrainian military helicopter.
The horrible accident that turned a quiet region in Eastern Europe into eerie ghost country.
CEO Elon Musk is filing a lawsuit to allow competition for contracts. "If SpaceX competes and loses, that's fine," he insists.
Russia's currency was downgraded Friday by S&P, and the rating may sink lower if further sanctions are imposed.