The scope of retaliatory actions or sanctions would depend on the severity of the hacks, the officials added.
US President Joe Biden, speaking hours after Ukraine reported its defense ministry and two banks had been hacked, told reporters earlier on Tuesday that Washington was coordinating closely with NATO allies and other partners to expand defenses against threats in cyberspace.
The attacks, believed by Western security experts to have been carried out by Russia, were not unexpected, US and European officials said, requesting anonymity.
"The president has said we will respond to Russian actions short of a military invasion," said one US official quoted by Reuters. "But what is decided depends on the extent of the cyberattacks. There are so many ranges, it's hard to go into specifics." READ MORE
