ABU DHABI- The chief executive of Ukraine's state energy company Naftogaz said on Monday he was still hopeful that Russia's Nord Stream 2 gas pipeline would not come online, saying it did not comply with European law.

Yuriy Vitrenko told Reuters in an interview on the sidelines of an energy conference in Abu Dhabi that he expected the German energy regulator's decision on whether to certify the pipeline this week.

"Yes, that's our expectation, because we believe that currently the operator is not compliant with European law," he said when asked if Ukraine still had hope of the pipeline not operating.

"We believe it should not be certified until it is compliant with European law."

Ukraine would lose about $2 billion per year if Nord Stream 2 came online, equivalent to roughly 1.5% of its GDP, Vitrenko said.

"We also expect that the U.S. Congress will impose sanctions on the operator because it's more or less clear on the other side of the pond at least that Russia is using gas as a weapon and it is not playing by the rules and that Nord Stream 2 is actually putting the whole continent and global security at risk," Vitrenko said.

(Reporting by Yousef Saba and Alex Lawler; Editing by Kirsten Donovan and Bernadette Baum) ((Yousef.Saba@thomsonreuters.com; +971562166204; https://twitter.com/YousefSaba))