In an unusual move, the White House on Tuesday recommended that investors avoid Russian stocks as the political rhetoric heated up in the dispute over Moscow declaring Ukraine's Crimean peninsula part of Russia.
"I wouldn't, if I were you, invest in Russian equities right now, unless you're going short," White House spokesman Jay Carney said, half smiling, at a press briefing.
Stressing that the United States was preparing a new round of sanctions, Carney told reporters that the long-term impact of Russia's bid to annex the Crimea region of Ukraine would have an impact on Russia's economy.
"They will also incur costs because of the sanctions that we and the EU have imposed," Carney said.
The United States and the European Union imposed travel bans and asset freezes on a handful of officials from Russia and Ukraine accused of involvement in Moscow's seizure of the Black Sea peninsula, most of whose 2 million residents are ethnic Russians.
Russia's stock market was hammered in the run-up to the weekend referendum in Ukraine's Crimea region in which voters overwhelmingly said they wanted to join Russia.
However, the market rallied on Monday and gained another 2 percent on Tuesday and the rouble rose after Russian President Vladimir Putin said Russia would not seek to further divide Ukraine.
Investors noted the initial sanctions did not target businesses or executives, but the White House has signaled a fresh round of sanctions could hit some on the business side.