The exchange involved Russian arms dealer Viktor Bout and U.S. basketball star Brittney Griner.

"The talks were exclusively on the topic of the exchange. It's probably wrong to draw any hypothetical conclusions that this may be a step towards overcoming the crisis in bilateral relations," the TASS news agency quoted Peskov as saying.

"Bilateral relations continue to remain in a sorry state," he added.

Anatoly Antonov, Russia's ambassador to the United States, later said 30 more embassy staff would have to leave on Jan. 1 because of visa restrictions, RIA news agency said.

"The Americans continue their policy of reducing Russia's diplomatic presence in the United States," it quoted him as telling Russian state television.

Antonov, echoing Peskov's earlier comments, said he did not see anything positive about the current state of bilateral ties, RIA said.

(Reporting by Reuters; Editing by David Ljunggren and Daniel Wallis)