Despite major cyber-attacks in the West so far not having materialised, a senior US intelligence official says that the ongoing cyber-conflict over Ukraine could escalate.

In an interview with the BBC, Rob Joyce, director of cyber-security at the National Security Agency, said that while a single massive attack hasn’t taken place, there has been a “sustained conflict” in the cyber realm.

So far, this has included Russia deploying eight or nine different viruses to wipe computer systems.

On Tuesday, the US, UK and EU accused it of targeting a satellite communications provider used by the Ukrainian military – an attack that also affected other customers in Europe.

Joyce added that US officials are concerned that Russia could increasingly turn to cyber-attacks as its campaign in Ukraine falters and sanctions bite on its economy.

“Our worry is that it’s a decision point,” he said. “When that decision point happens, there certainly is capability to come after some of that [Western] infrastructure.”