Initial State Duma hearings on the New START arms reduction treaty with the United States have elicited no serious opposition, a senior lawmaker said Thursday.

In sharp contrast, Republican lawmakers in Washington were grilling White House officials this week about whether the treaty offered concessions to Russia.

The pact, signed by Presidents Barack Obama and Dmitry Medvedev in April, must be ratified by legislators in both countries to go into force.

"I can only say that the representatives of all factions had no complaints about the text of the treaty," said Konstantin Kosachyov, chairman of the Duma's International Relations Committee, Interfax reported.

Kosachyov said some deputies expressed disappointment about unspecified issues they felt should have been given more attention in the treaty, but indicated that they would be have to be dealt with in future agreements.

Kosachyov spoke after closed-door hearings involving his committee and the Duma's Defense Committee.

Medvedev, signaling that he does not want Russia to commit to the pact until it is clear that the United States will do so, has urged deputies to ratify it at the same time as the U.S. Senate.

Deputy Foreign Minister Sergei Ryabkov told reporters that he expected "there will be difficulties" in the ratification hearings because "there is great interest in this issue in Russian society and the parliament," Itar-Tass reported.

But analysts said Duma approval is virtually assured as long as the Senate ratifies the treaty.

In Washington, Secretary of State Hillary Clinton sought to reassure senators on Thursday that the pact would not constrain U.S. missile defenses.

Clinton noted that the Russian government has stated that it reserves the right to withdraw from the treaty if it feels threatened by an expansion of U.S. defenses against ballistic missiles.

"But that is not an agreed upon view, that is not in the treaty," Clinton told the Senate Armed Services Committee. "It's the equivalent of a press release, and we are not in any way bound by it."

Clinton said the United States has issued its own statement about missile defenses, "making clear that the United States intends, and in fact is continuing, to improve and deploy effective missile defense systems."

Some Republican members of Congress have questioned whether the treaty imposes limits on U.S. missile defenses.

Clinton testified on the treaty alongside Defense Secretary Robert Gates, Energy Secretary David Chu and Admiral Mike Mullen, chairman of the Joint Chiefs of Staff. All four urged the Senate to ratify the pact as soon as possible.

On Wednesday, the chief of the Pentagon's Missile Defense Agency also assured senators that the treaty did not limit Washington's missile defense plans.

"There are no limitations in the treaty that affect our plans for developing missile defense," Lieutenant General Patrick O'Reilly told the Senate Foreign Relations Committee.

Republican Senator James Risch asked whether a clause in the New START that prohibits the conversion of long-range missile launchers into missile defense launchers was not a constraint.

O'Reilly replied that the clause was nothing to worry about because the actions it prohibits were not planned anyway.

While the United States did five such launcher conversions back in 2002, no more were planned, he said. This was because officials had learned that it is cheaper to build launchers, and easier to maintain them, than to convert old ones.

"The options that are prohibited would be ones that we would not choose," O'Reilly said.

O'Reilly's appearance with two other Pentagon officials came a day after the treaty's chief U.S. negotiator told lawmakers that there were no secret deals to limit missile defense made with Moscow during talks on the pact.

(Reuters, AP, MT)