Russian hacking of US should be considered 'act of war'

Alleged Russian hacking of the US should be considered "an act of war", Republican Senator John McCain has said.

Mr McCain said a lot more needs to be done in response to the hacks, saying America needs to make sure there is a price to pay.

The former presidential candidate made the remarks after President Barack Obama's administration unleashed a string of sanctions and ordered that 35 Russians be expelled from the US amid allegations of Russian meddling in the American presidential election.

"When you attack a country, it's an act of war," Mr McCain said on a visit to Kiev.

"And so we have to make sure that there is a price to pay, so that we can perhaps persuade the Russians to stop these kind of attacks on our very fundamentals of democracy."

Mr McCain said it was possible to impose many sanctions on Russia, including financial institutions, individuals and organisations.

He has scheduled a hearing for Thursday on foreign cyber threats.