The Kremlin said on Monday that Russia would establish which state or states were behind blasts that damaged the Nord Stream gas pipelines and would do everything to stop what it called Western efforts to "cover-up" what happened.
The pipelines, which connect Russia and Germany under the Baltic Sea, were hit by unexplained blasts last September in what Moscow called an act of international terrorism.
President Vladimir Putin has said he believes the United States was behind the blasts, an idea Washington has rejected as false.
A Russian diplmat said earlier on Monday that Moscow may seek compensation for the pipeline damage, but did not specify from whom.