MOSCOW - Moscow and Washington have started "a war of nerves" over the so-called Magnitsky Act, threatening bilateral relations, Russian Deputy Foreign Minister Sergei Ryabkov said Monday.

Russia hopes that US President Barack Obama would not consider an online petition to him to identify Russian politicians who initiated a tit-for-tat bill and make them liable under the Magnitsky Act, Ryabkov said.

Russia's lower house of parliament on Friday passed a bill that bans US citizens from adopting Russian orphans. The so-called Dima Yakovlev bill is named after a Russian boy who died in the United States due to his foster parents' negligence.

The move was in response to the US Magnitsky Act, which imposes a visa ban and asset freeze on Russian officials thought responsible for the death of anti-corruption lawyer Sergei Magnitsky in 2009 in a Moscow jail.

Russia and the United States, Ryabkov said, should ease the tension instead of stirring up troubles.

"I'd like to believe the common sense will prevail and we will not enter a new stream of completely senseless and harmful confrontation over a question which should not exist at all," he said.

Also on Monday, Russian Foreign Minister Sergei Lavrov expressed reservations about the Dima Yakovlev bill, or the "anti-Magnitsky" bill.

Speaking on the Russia Today TV channel, he said the bill, if passed, might have negative consequences for Russian children already adopted in the United States.

He added that Moscow should try to keep the Russia-US agreement on children adoption which came in force this November.

The Federation Council, the upper house of parliament, will consider the "anti-Magnitsky" bill on Wednesday. If passed, the bill will be sent to President Vladimir Putin for signing.

It could become law on January 1 should Putin put his name on it.