By Andrew Quinn and Gleb Bryanski
VLADIVOSTOK, Russia (Reuters) - The U.S. Congress could move this month to upgrade trade relations with Moscow, Secretary of State Hillary Clinton said on Saturday, but Russia made clear after talks that big differences remained on Syria and Iran.
Clinton, in Russia for a summit of countries on the Pacific Rim, said the U.S. government was working closely with Congress on lifting the 1974 Jackson-Vanik amendment, Cold War-era legislation that has blocked normal trade privileges for Russia.
Changing the legislation is an important part of President Barack Obama's efforts to bolster ties with Russia.
"To make sure our companies get to compete here in Russia, we are working closely with the United States congress to terminate the application to Jackson-Vanik to Russia and grant Russia permanent normalized trade relations," Clinton told business leaders in the Pacific port city of Vladivostok.
"We hope that the Congress will act on this important piece of legislation this month," she said in a speech before the start of the Asia-Pacific Economic Cooperation (APEC) summit.
Congress is under pressure to approve the permanent normal trade relations (PNTR) bill because of Russia's entry into the World Trade Organization (WTO), a move the United States backed.
But with concerns in Congress about Moscow's support for Iran and Syria, as well as its broader human rights record, the timing of a vote remains unclear.
Congress could add further conditions to any PNTR legislation, including a measure known as the "Magnitsky bill" to punish Russian officials for alleged human rights violations.
Republican presidential candidate Mitt Romney, who has called Russia the "number one geopolitical foe" of the United States, has said he will back PNTR for Russia only if it is accompanied by a measure to target human rights violations.
U.S. officials said Clinton had raised the broad question of human rights at a one-hour meeting with Foreign Minister Sergei Lavrov, but Lavrov denied the issue came up specifically.
"We did not discuss this issue because the U.S. side knows perfectly well that attempts to replace anti-Soviet legislation with anti-Russian legislation are unacceptable. They know it will inflict real damage to our relations," Lavrov said.
He also told reporters the sides remained divided on foreign policy issues such as the Syrian conflict and Iran's nuclear program.
"Our U.S. partners prefer measures like threats, increased pressure and new sanctions against both Syria and Iran. We do not agree with this in principle," Lavrov said.
STANDING IN FOR OBAMA
Clinton is standing in at the summit for Obama, who is preparing for the November presidential election.
U.S. officials say Clinton's trip is partially aimed at assessing Russia's push to expand engagement in Asia, which parallels Washington's "pivot" to the Asia-Pacific region after the military campaigns in Iraq and Afghanistan.
Clinton intended to tell President Vladimir Putin in talks later on Saturday the United States welcomed a bigger Russian role in the region and was seeking to build more cooperation, the officials also said.
Moscow and Washington have been working in concert with other permanent members of the United Nations Security Council to pressure Tehran over its nuclear program.
On Syria, Washington has accused Moscow and Beijing of blocking efforts at the Security Council to approve tough measures against Damascus as it battles an armed rebellion.
The United States has angered Russia by going outside the United Nations to work with allies to support the Syrian opposition, but Clinton told Lavrov it was possible to return to the United Nations if Moscow and Beijing were ready to forego their vetoes and back stronger measures.
A U.S. official said Clinton, who also visited China this week, made the same comments to Chinese leaders.
Lavrov said Russia expected the Security Council later this month to formally endorse an agreement brokered by former U.N. Syria envoy Kofi Annan which envisages a transitional governing authority for Syria.
(Editing by Douglas Busvine, David Brunnstrom and Janet Lawrence)