U.S. Trade Representative Ron Kirk said Thursday that the repeal of a U.S. law that can be used to put trade restrictions on Russia is a top priority for his office this year.

The Cold War-era Jackson-Vanik amendment denies normal trading arrangements to non-market countries that restrict emigration. It was originally a reaction to hurdles the Soviet Union put up for Jews who wanted to leave the country in the 1970s.

Although Russia has not restricted emigration in any way since 1991 and the U.S. has granted Russia annual waivers since 1994, the law remains in force and is an irritant to investors and Russian politicians.

Russia has wrapped up negotiations on membership in the World Trade Organization, and its parliament is expected to ratify Russia's membership on July 4.

"Once Russia becomes a member of the World Trade Organization, we need to make sure that American businesses have the full advantages of that, and therefore it's necessary for us to lift Jackson-Vanik," Kirk told the American Chamber of Commerce in Russia.

Some U.S. lawmakers have indicated they would support repeal of Jackson-Vanik in exchange for passage of the so-called Magnitsky bill that would bar Russian officials accused of human rights abuses from the United States.

That bill calls for publicly identifying Russians tied to human rights abuses, but the Obama administration worries that could affect relations with Moscow. The bill was introduced by two Democrats and also is backed by prominent Republicans, including Sen. John McCain.

The bill was named for lawyer Sergei Magnitsky, who had accused Interior Ministry officials of corruption. He died in jail in 2009 from untreated pancreatitis.

Proponents of the bill say the death, and allegations of torture in jail, highlight corruption in Russia's judicial system.

Prospects for passing the measure as a stand-alone bill are uncertain, and senators saw an opportunity to boost its chances by tying it to the repeal of Jackson-Vanik.

Kirk said the two measures should not be linked.

"Our priority is for the Congress to lift Jackson-Vanik in a clean bill which deals only with the issue relevant to our ability to maintain our competitiveness," he said, adding the administration will "continue our work" with lawmakers concerned about Russian human rights.