The Kremlin said on Wednesday that Russia must be part of investigations into last week's explosions in the two Nord Stream gas pipelines under the Baltic Sea.

"So far, from those news conferences which took place in Denmark and Sweden, we've heard disturbing statements that any cooperation with the Russian side is ruled out," Kremlin spokesman Dmitry Peskov said.

"We, obviously, will be waiting for some clarification on that as we believe that, definitely, participation of the Russian side in examining the damaged area and investigating what happened should be mandatory."

European governments and NATO say the two Nord Stream pipelines were attacked in an act of sabotage, which has further roiled global energy markets after months of tension and disrupted supplies since Russia's invasion of Ukraine.

President Vladimir Putin on Friday blamed the United States and its allies, allegations rejected by Washington. Russia has rejected what it called "stupid" theories in the West that it sabotaged the pipelines itself.

The operators of the two pipelines between Russia and Germany have said they are currently unable to inspect the damaged sections because of restrictions imposed by Danish and Swedish authorities, in whose waters the blasts and leaks occurred.

Nord Stream 2 AG, Switzerland-based operator of the second pipeline, said on Tuesday it will examine the condition of the leaking pipelines once a police investigation of the "crime scene" is completed and a cordon is lifted.

Later on Tuesday, Nord Stream AG, operator of the older Nord Stream 1 pipeline, said it had been told by Danish authorities that receiving the necessary permits to carry out an inspection could take over 20 working days.