Image copyright EPA Image caption The three US senators have been touring the Baltic states together

Three prominent US senators have warned that Russia and its president may face sanctions over the country's alleged interference in last month's presidential election.

They said the move had cross-party support in the senate.

President-elect Donald Trump has rejected claims of Russian interference.

Outgoing President Barack Obama is expected to announce retaliatory measures as early as Thursday.

These could include economic sanctions and changes to diplomatic relationships.

Russian foreign ministry spokeswoman Maria Zakharova responded in a statement: "If Washington really does take new hostile steps, they will be answered.

"Any action against Russian diplomatic missions in the US will immediately bounce back on US diplomats in Russia."

Earlier this month, CIA officials told US media they had "high confidence" that Russian hackers had attempted to sway the US election in Mr Trump's favour.

The Trump team responded to those reports by saying "these are the same people that said Saddam Hussein had weapons of mass destruction".

Republicans John McCain and Lindsey Graham, and Democrat Amy Klobuchar, voiced their support for sanctions on Wednesday while visiting the Baltic states of Estonia, Latvia and Lithuania, which are Nato members close to Russia's western edge.

Mr Graham told CNN the proposed sanctions would "hit Russia hard, particularly (President) Putin as an individual.

"I would say that 99 of us (senators) believe the Russians did this and we're going to do something about it."

He told reporters: "Russia is trying to break the back of democracies all around the world. It is now time for Russia to understand - enough is enough."

The EU is still sanctioning Russia over its 2014 annexation of the Crimea peninsula. The sanctions, which target Russian arms exporters, banks and individuals blamed for the pro-Russian insurgency in Ukraine, have taken a heavy economic toll on Russia to date.