A media report says new intelligence reviewed by US officials suggests a pro-Ukrainian group was responsible for massive gas leaks from undersea pipelines between Russia and Germany last year.
Four gas leaks occurred on two Nord Stream pipelines in the Baltic Sea in late September.
The Ukrainian government is denying involvement in them.
The New York times reported on Tuesday that, "New intelligence reviewed by US officials suggests that a pro-Ukrainian group carried out the attack on the Nord Stream pipelines last year."
The report says the newly collected intelligence indicates that the members of the group "were opponents of President Vladimir Putin of Russia, but does not specify the members of the group, or who directed or paid for the operation."
It says, "Officials who have reviewed the intelligence said they believed the saboteurs were most likely Ukrainian or Russian nationals, or some combination of the two."
It quotes US officials as saying that they had no evidence of involvement by Ukrainian President Volodymyr Zelenskyy or Ukrainian government officials.
White House National Security Council spokesperson John Kirby told reporters on Tuesday that countries including Sweden and Denmark are investigating the gas leaks.
Kirby said observers "need to let these investigations conclude."
A senior adviser to Zelenskyy, Mykhailo Podolyak, posted on Twitter that Ukraine "has nothing to do with the Baltic Sea mishap." He said he had no information about pro-Ukrainian "sabotage groups."
Russia's deputy ambassador to the UN, Dmitry Polyanskiy, tweeted, "This proves that we are right pushing for a UN Security Council resolution on launching an international investigation on the Nord Stream sabotage, led by the UN Secretary General."