(Reuters) - A senior Republican senator on Thursday warned the White House that passing legislation to bolster trade relations with Russia won't be a slam dunk because of concerns over that country's record on human rights and foreign policy actions.

It's simply unreasonable to believe that PNTR (permanent normal trade relations) can be extended to Russia without a more thorough examination of the issues, Senator Jon Kyl, the No. 2 Republican in the Senate, said at a hearing.

With Russia on the verge of joining the World Trade Organization, the United States is under pressure to repeal a largely symbolic Cold War-era provision known as the Jackson-Vanik amendment that is at odds with WTO rules.

The measure tied trade relations with the former Soviet Union to the rights of Jews and other religious minorities to emigrate freely. The Soviet Union collapsed two decades ago, and Russia has been judged to be in compliance with the Jackson-Vanik provision since the 1990s.

Senate Finance Committee Chairman Max Baucus, a Montana Democrat, is a strong proponent of repealing the measure and granting permanent normal trade relations to Russia.

Failure to do that could deny American companies the market-opening benefits of Russia joining the WTO, he said.

WTO members approved Russia's entry in December, and the country is expected to formally become a member this summer, 30 days after the Russia Duma passes legislation to implement remaining commitments under its WTO accession agreement.

But at a Finance Committee hearing to examine the issue, Kyl said he had very strong reservations.

I think I understand the message that this hearing is intended to convey: American businesses want access to Russia's market. We should repeal Jackson-Vanik, grant Russia permanent trade relations without delay and without conditions. It's a slam dunk. But it isn't a slam dunk, he said.

While immigration is no longer an issue, Russia's blatant disregard for human rights and the rule of law is every bit as relevant as it was decades ago, Kyl said.

The Arizona Republican also raised concern with Russia's support for Syrian President Bashar al-Assad's bloody crackdown on anti-government protests.

In recent months, Moscow has not only blocked U.N. Security Council action on Syria but has continued to sell arms to Assad's regime which is responsible for the slaughter of innocent citizens. This is not a government to be trusted to uphold its international commitments or give a fair shake to American businesses, Kyl said.