Russia's Federation Council, the upper house of parliament, was expected to endorse the annexation of Crimea at a meeting on March 21.
The vote in the upper house comes after the State Duma, or lower house, overwhelmingly approved the annexation treaty on March 20.
Ukraine's parliament on March 20 said in a resolution that Kyiv will never recognize Russia's annexation of the Black Sea peninsula.
The resolution said Ukraine "will never cease to fight for the liberation of Crimea as long and painful as this can be."
On March 20, Russia and the United States slapped sanctions upon each other as tensions over Ukraine continue to rise.
"Based on the executive order that I signed in response to Russia's initial intervention in Ukraine, we are imposing sanctions on more senior officials of the Russian government," U.S. President Barack Obama told reporters in Washington.
"In addition, we are today sanctioning a number of other individuals with substantial resources and influence who provide material support to the Russian leadership, as well as a bank that provides material support to these individuals," he said.
The new sanctions target 20 individuals, including President Vladimir Putin’s chief of staff and close associate Sergei Ivanov, as well as Bank Rossiya, which has close ties to the Russian leadership.
The U.S. Treasury called Rossiya "the personal bank for senior officials of the Russian Federation." A senior Obama administration official said the bank will be "frozen out of the dollar," or unable to conduct transactions in the American currency.
Other Russians facing an asset freeze include the speaker of the State Duma lower house of parliament, Sergei Naryshkin, the leader of the A Just Russia party Sergei Mironov, and Rossiya Bank chairman Yuri Kovalchuk.
Obama also said he had signed an order clearing the way for the United States to impose sanctions on sectors of the Russian economy.
A senior U.S. administration official noted that the intent was to signal that "if there is further escalation, for instance military intervention in southern and eastern Ukraine, that we are prepared to target entities in these very significant sectors of the Russian economy.”
Minutes after Obama’s announcement, the Russian Foreign Ministry released its list of Americans targeted for sanctions.
It said six lawmakers -- Robert Menendez, Mary Landrieu, John McCain, Daniel Coats, and Senate Majority Leader Harry Reid; House of Representatives Speaker John Boehner -- and three presidential aides -- Caroline Atkinson, Daniel Pfeiffer, and Benjamin Rhodes -- are barred from entering Russia.
Also on March 20, the defense chiefs of the United States and Russia spoke by telephone about the deployment of thousands of Russian troops near the Ukrainian border.
The Pentagon says Russian Defense Minister Sergei Shoigu pledged to U.S. Defense Secretary Chuck Hagel that Russian forces will not cross the border into eastern Ukraine.
"[Shoigu] gave three assurances, which I have outlined for you: it's an exercise only, no intention of crossing the border into the Ukraine, not going to take any aggressive action. That was Mr. Shoigu's words and Secretary Hagel's expectations is that he will live up to those words," Pentagon spokesman John Kirby told reporters in Washington.
The annexation of Crimea -- an autonomous republic of Ukraine -- has been rejected by the United States and other Western nations as illegal.
Based on reporting by Reuters, AP, and AFP