After months of hesitation, the European Union announced that it will join the United States in its economic sanctions against Russia in response to the country's support of separatists in Ukraine. President Obama also promised today expanded sanctions by the U.S. that will "have an even bigger bite."

"The cost on Russia will continue to grow," Obama said at the White House today. "Today is a reminder that the United States means what it says." Like previous sanctions by the U.S., the EU's will target banks, energy, and arms firms. From the Wall Street Journal:

The trade and investment restrictions agreed by EU governments in Brussels marked a major escalation of sanctions against Russia, which so far have been mostly token measures targeting individuals. Measures targeting Russia's banks, oil industry and military could increase financial strains in its already sluggish economy while withholding technology that the nation's modernization relies on.

The U.S. followed the EU's move by announcing similar sanctions against Russian banks as well as the energy, arms and shipping sectors. President Barack Obama hailed Europe's adoption of its most significant sanctions yet against Moscow, saying the parallel U.S.-EU steps would have "bigger bite."

"It is now up to the Russian leadership to decide whether it wants to take the path of de-escalation and cooperation," German Chancellor Angela Merkel said today. "The EU's sanctions can be reviewed, but additional steps are also possible."

The Washington Post reports that these new sanctions by the EU against Russia are the toughest since the Cold War:

Analysts say the restrictions could inflict serious damage on the already listing Russian economy, which relies heavily on Europe as a market for its oil and gas, as a source of financing and as a supplier of components for its military. All three areas will take a hit under the measures announced Tuesday.

"The issue is how do we prevent bloodshed in eastern Ukraine...and the main tool that we have to influence Russian behavior at this point is the impact it's having on its economy," Obama said.

[Image via AP]