Moscow sees no sign of progress in its dialogue with Washington on the US-led anti-ballistic missile shield, since there are major discrepancies in their takes on the matter, Russia's deputy chief of foreign affairs said.

"I can't say we are standing on the doorstep of a breakthrough or some major shift on the remaining stumbling-stone problems or the ABM, as well as on other means of nuclear arms control. I have no grounds for that," Mr. Ryabkov said.

He confirmed that the guarantees, offered by the US on its anti-ballistic shield, were tabled at his August 5 meeting with US arms control official Rose Gottemoeller.

"We signaled that the proposals US gave us this spring got our attention. This is clearly a step in the right direction, although it is not enough to reach a compromise," the minister said.

He underscored that the offer "lacked the key element that would allow us to check if the claims that the American missile system was not targeting Russia and that it was not there to undermine Russia's nuclear potential matched the truth."

"Until we come up with a formula or a plan that would let us prove the system's true colours instead of putting our trust in these allegations, there will be no compromise in sight," the diplomat warned.

He said the status quo was that "America's ideas and our concerns sort of exist in different planes, different dimensions, and any cross-points are yet to be found."

He added, however, the US and Russia were working together without "dramatizing" the split in their stands. "We have never been under the illusion we'll be able to agree on the ABM."

"The US did not quit the 1972 ABM treaty to commit itself again without a second throught," he explained.

He told reporters the missile shield would be discussed at the upcoming August 9 summit in Washington that is expected to bring to the negotiating table foreign and defense ministers of both countries.

Russia's Deputy Foreign Minister Sergei Ryabkov has said there will hardly be any non-proliferation progress until Moscow and Washington agree on the disputed missile shield and other urgent issues that put strategic stability at risk.

"The total sum of all strategic stability factors suggests that the chance for deeper nuclear weapon cuts is all but non-existent," Mr. Ryabkov said.

The Russian minister stressed that no further arms reductions could be brought into question unless the countries made a sufficient progress on other strategic matters.

He underscored that Russia saw the link between the START treaty and the US-backed anti-ballistic missile shield in Europe as "axiomatic and absolutely irrefutable."

"Without an ABM agreement that would allay our worries, there can be no progress on nuclear non-proliferation," he said, adding any concrete agreement on the issue was nowhere in sight.

Mr. Ryabkov continued to say the missile shield controversy was not the only roadblock on the way to strategic stability. Among other key problems, he said, is the spiraling arms race in the outer space and the issue of non-nuclear missile-carriers.

The Russian diplomatic high-flier deplored the rift that divided Moscow and Washington on the majority of these controversies, adding space safety had recently brought the two nations closer to each other.

"Our cooperation in this sphere is not close enough, although we have found more points of mutual interest lately as far as space safety goes," Ryabkov confessed.

Russia has condemned the links that media have recently hinted at between its fugitive intelligence contractor Edward Snowden and the future of US-jailed Russian nationals that are serving lengthy prison terms on dubious charges.

Russia's Deputy Foreign Minister Sergei Ryabkov dismissed the claims that the cases of Snowden, convicted arms trafficker Viktor Bout and alleged smuggler Konstantin Yaroshenko followed a similar pattern, saying "we are not drawing any parallels between the situation around Snowden and these particular instances."

"The circumstances are quite different," he stressed.

Mr. Ryabkov said that trials of Russian nationals by US courts were a clear trend, while Snowden's asylum in Russia was a logical move.

"Snowden considered all circumstances and took the imitative," he explained.

"Using his fate and personal perspectives as a bargaining chip now won't do."

The minister complained about the US tendency to "lure or abduct" Russian citizens who are then tried by a US court. "It is poison to the atmosphere of bilateral relations," he vowed, adding the issue was an unabating source of controversies between the two nations.

He added the US still hadn't responded to Russia's proposal to enact the Council of Europe's 1983 Convention on the Transfer of Sentenced Persons.

"We see it as one of viable plans. But even on this matter the reaction was vague," Mr. Ryabkov fumed.

He stressed that imprisonments of Bout and Yaroshenko, among others, had a significant negative impact on the relationship between Moscow and Washington.

Moscow has confirmed that several US citizens from the so-called "Guantanamo list" were barred from entering Russia.

"In several instances, American officials were denied Russian visas because these people - I won't give you their names - stood on our list," Russia's Deputy Foreign Minister Sergei Ryabkov told reporters.

The Guantanamo list was compiled as a retaliatory measure after the US Congress passed its Magnitsky Act.

The Russian list consists of people who allegedly transgressed against human rights freedoms, including Russian nationals abroad.