The administration reached out to European officials in recent days to assure them that Mr. Obama would implement the new legislation as part of their joint efforts to keep Mr. Putin from driving a wedge among the Western nations. European officials are talking about imposing new sanctions in the coming days specifically related to Russia’s annexation of Crimea, but they almost certainly would not go as far as the new American legislation contemplates.

Some analysts said Mr. Obama had little choice but to sign the legislation since Russia has continued to violate the terms of a cease-fire negotiated months ago in Minsk, the capital of Belarus.

“Given Russian military resupply of the separatists in Ukraine during the last month, the U.S. had to raise the economic costs to Putin for his outright aggression,” said R. Nicholas Burns, a former diplomat and undersecretary of state under President George W. Bush. “Combined with the collapse of the ruble, sanctions will hit Putin’s government where it is most vulnerable — its very shaky economy.”

But it is not clear how much of the authority granted under the legislation Mr. Obama will invoke. The bill requires the president to impose at least three sanctions from a menu of nine options on Rosoboronexport, the main Russian state arms exporter, and other military companies accused of fostering instability in Ukraine, as well as in Moldova, Georgia and Syria. But it includes a provision allowing him to waive the requirement if he concludes that doing so would be in the nation’s security interest.

The legislation also authorizes the president — but does not require him — to impose sanctions on international companies that invest in certain types of unconventional Russian crude-oil energy projects and to further restrict the export of equipment for use in Russia’s energy sector. And it authorizes the president to bar investment or credit to Gazprom, the Russian state energy giant.

In addition, the legislation authorizes the provision of lethal arms to the Ukraine government, including antitank weapons, tactical surveillance drones and counter-artillery radar. Mr. Obama has resisted sending weaponry to Kiev on the theory that it would only escalate the fighting in eastern Ukraine, so it is not clear whether he will follow through on the authorization.

The measure went beyond only penalties to authorize $10 million in each of the next three fiscal years to counter Russian propaganda in the former Soviet Union and prioritize Russian-language broadcasting in Ukraine, Moldova and Georgia. And it authorized $20 million in each of the next three years to promote democracy, independent news media, uncensored Internet access and anticorruption efforts in Russia.