Russia criticised Western moves to expand a planned United Nations probe into chemical weapons in Syria and compared it to the build-up to the U.S. invasion of Iraq.
Russia, which has used its clout as a veto-wielding Security Council state to blunt Western pressure on Syria, says the U.N. probe announced last month should focus on Syrian government allegations rebels used chemical arms near Aleppo.
Western countries want two additional rebel claims about the use of such arms investigated as well. The Syrian opposition says President Bashar al-Assad's government carried out all three alleged chemical attacks.
In a pointed statement, Russia's Foreign Ministry on Saturday voiced anger over a letter in which it said the U.N. Secretariat told the Syrian government it intended to broaden the investigation beyond the incident in late March near Aleppo.
It said the U.N. Secretariat was seeking overly broad access for investigators to facilities and individuals in Syria and wanted to use aircraft for transportation.
"This approach brings to mind the line taken over an investigation into the presence of chemical weapons in Iraq, which was based on deliberately false data and led to well-known consequences," it said, referring to the U.S.-led invasion in 2003.
"We cannot fail to draw the conclusion that under pressure from certain states, the U.N. Secretariat is taking an unconstructive and inconsistent position that in essence undermines the investigation (into the incident near Aleppo)," it said, without mentioning U.N. Secretary General Ban Ki-moon by name.
Last month, Russia accused Western nations of trying to use the investigation to push Assad from power and said the probe might be biased unless Russian and Chinese experts were part of the team of investigators.
Russia says that it does not intend to prop up Assad but that his departure from power must not be a precondition for a political solution to the conflict.
More than 70,000 people have been killed during Syria's two-year conflict.