MADRID, February 4. /TASS/. The Spanish newspaper El Pais neither confirmed nor denied the US statement that Russia was allegedly involved in the leak of a confidential document that contained the response to Russian security proposals, Lucia Abellan, chief international editor at El Pais, told TASS on Friday.

"I can neither confirm nor deny, because we cannot disclose the sources," she said. Abellan said the US might be suspecting Russia of involvement in the leak because Russian Foreign Minister Sergey Lavrov and other officials said from the very beginning that "they want the documents to be published."

"That means they were the side that showed it would rather this were published," she said.

On Wednesday, the Spanish El Pais newspaper released the documents containing the US and NATO responses to Russia’s proposals on security guarantees. The responses suggest the US and NATO are ready to discuss the issues of security in Europe with Russia but disagree with its key demands that the alliance stop expanding eastward and roll back its military infrastructure to where it was in 1997.

Subsequently, US Under Secretary of State for Political Affairs Victoria Nuland told TASS that Russia "put out in public" a confidential US document containing the US responses to Moscow’s security proposals. "We’re pretty confident in the sense that the markings on the document were the same as those that we gave to the Russian Federation," the diplomat said. "The copies of the document that were given to allies had different markings on them."

Kremlin Spokesman Dmitry Peskov rejected Nuland’s statement. "Our US colleagues very often are sure about things that later prove to be untrue," he said.