The President announced that his administration had authorized the blockage of exports of specific goods and technologies that benefit Russia's energy sector, and increased sanctions on Russian banks and defense companies. Obama also said that he authorized the suspension of credit that encourages exports to Russia and financing for development projects in the country.
Obama said the new sanctions will increase the pressure on "the cronies and companies that are supporting Russia's illegal actions in Ukraine."
Explaining the newest sanctions, Obama cited Moscow's continued arming and encouraging of Ukrainian separatists, intelligence that indicates forces inside Russia have launched artillery strikes into Ukraine, and the continued increase of Russian military along the border.
"Today Russia is once again isolating itself from the international community, setting back decades of genuine progress," Obama said. "And it doesn't have to come to this. It didn't have to come to this. It does not have to be this way."
American sanctions will have "an even bigger bite" for Russia because of their coordination with European sanctions, the president said, adding that Russia's economy has already suffered at the hands of Western sanctions.
Obama said that his administration had "made it clear that if Russia continues on its current path, the cost on Russia will continue to grow."
"And today is a reminder that the United States means what it says," Obama added.
In response to a question from the press pool, Obama emphasized that the sanctions do not represent a new Cold War, but are instead specifically tied to Moscow's actions in Ukraine.
Earlier Tuesday, Obama wrote to Russian President Vladimir Putin to inform him directly that the U.S. government had determined that Russia violated the intermediate-range nuclear treaty, according to White House spokesman Josh Earnest.
"That is an indication that this is a matter that merits the serious attention of the leaders of both the United States and Russia," Earnest told reporters at a briefing, declining to provide details on how Russia violated the treaty.
The United States also slapped sanctions on VTB, the Bank of Moscow, the Russian Agriculture Bank and the United Shipbuilding Corp over Moscow's support for separatists in eastern Ukraine, the Treasury Department said.
That expands the list of Russian banks subject to U.S. sanctions to almost all the largest banks with state ownership of over 50 percent, except for Sberbank.
The sanctions on the three banks prohibit U.S. citizens or companies from dealing with debt carrying maturities longer than 90 days, or with new equity. The sanctions on the shipbuilding company, based on St. Petersburg, freeze any assets it may hold in the United States and prohibits all U.S. transactions with it.
—By CNBC with wires