Washington and Moscow are unlikely to reach agreement on massive nuclear arms reduction, despite Russian President Dmitry Medvedev's claims that "95 percent" of the treaty has already been agreed, a senior Chinese military strategist has said.

"It is of no use, even if they agreed on 99 percent of the treaty, if they are still at odds on the remaining 1 percent," said Peng Guangqian, a Beijing-based military expert who is close to Russian military resources.

Medvedev told reporters in the Black Sea town of Sochi on Sunday "everything in negotiations is going fine, 95 percent of the new deal's issues have been agreed upon".

But he also said that US plans for a missile defence system in Europe remained an issue.

US President Barack Obama and Medvedev laid out plans last year to forge a successor to the Strategic Arms Reduction Treaty, START-1, which expired on December 5.

The START-1, signed in 1991 between the Soviet Union and the United States, obliged both sides to reduce the number of their nuclear warheads to 6,000 and delivery vehicles to 1,600.

However, negotiators failed to reach an agreement by the original December 5 deadline, and official negotiations in Geneva have yet to resume after a break over the holiday period.

A top US official indicated earlier this month that they would resume on January 25, and Russia's Foreign Minister Sergei Lavrov said on Friday that he expected an agreement could be reached soon once negotiations resumed.

Issues still to be resolved include monitoring and verification measures.

But Peng said the remaining issues are all key ones.

"Nearly two months have passed since the deadline," Peng said. "Why? Because they are deeply at odds on strategic interests."

For example, although Obama said he has temporarily ceased the building of anti-ballistic base in Poland, a move welcomed by Medvedev, "it doesn't mean it will not be resumed, and of course Moscow knows that," Peng said.

Russian Prime Minister Vladimir Putin said in late December that US plans for the missile defence system were the main obstacle to reaching a new deal, causing the US State Department to reject any attempt to broaden START talks to cover defensive weapons systems.

On Sunday, Medvedev said the Kremlin "will definitely raise the issue" of the missile shield with its US negotiators once talks resume.

"It is crafty to speak of strategic nuclear forces without touching upon missile defence," Itar-Tass quoted him as saying. "If nuclear missiles are launched, anti-missiles are too."

But both sides still want the talks to continue, "as nobody wants to carry the moral burden of destroying them," Peng said. "Besides, deals under the treaty can maximize their national interests."

The issue is to be discussed at a nuclear summit raised by Obama, which is under preparation and is likely to gather leaders of several nuclear powers in April, Peng said.

Denuclearization will be a hot topic this year, and the importance of nuclear arms will keep increasing, that makes it even harder to realize a massive reduction, he added.

However, Li Daguang, a military specialist with the University of National Defense, said arms reduction is still possible.

"And even a small reduction is good for China's security and a peaceful world," he said.