The U.S. Senate is scheduled to vote later on December 6 on legislation that would end Cold War-era restrictions on trade with Russia and Moldova but also impose sanctions on alleged human rights violators in Russia.
Last month, the House of Representatives approved the legislation, which grants "permanent normal trade relations" to Moscow. That would allow U.S. companies to take advantage of the benefits from Russia's entry into the World Trade Organization in August.
But the legislation also requires the United States to freeze assets and deny visas to Russian officials implicated in the death of anticorruption lawyer Sergei Magnitsky and in other perceived gross violations of human rights.
Magnitsky died in torturous prison conditions in 2009 after exposing a massive fraud scheme.
On the eve of the vote, senators debated the bill.
Many argued that passage of the Magnitsky Act would provide the United States with a powerful tool to advance human rights in Russia.
Senator Benjamin Cardin, who co-sponsored the bill, said its passage would put the United States "on the right side of history."
"It will deepen our relationship with the Russian people. We are starting a new chapter on human rights, one that we can be proud of, where America, once again, is establishing a basic principle that we will not tolerate those who violate internationally recognized human rights standards," Cardin said.
"We will not let them go without being held accountable," he continued," and we certainly will not let them have the privileges of our country."
That message was echoed by Senator John McCain, who said the bill would benefit Russia as well.
"There are still many people who look at the Magnitsky Act as anti-Russia. I disagree. I believe it is pro-Russia. I believe it is pro-Russia because this legislation is about the rule of law and human rights and accountability, which are values that Russians hold dear," McCain said.
Russia has threatened retaliation if the provision gets final approval.