Donald Trump’s nominee for Secretary of State appeared to disagree on some issues with the President-elect when he testified before the Senate Foreign Relations Committee.

Rex Tillerson said he supported current US sanctions against Russia after hearing the revelations about alleged attempts by the Kremlin to interfere with the 2016 presidential election.

While Mr Trump has reluctantly conceded that Russian operatives may have been behind the hacks of the Democratic National Committee, he has insisted that they in no way had an effect on the outcome of the election.

But the CIA, FBI, and NSA – the agencies behind the highly classified report delivered to both Mr Obama and Mr Trump – did not reach that conclusion, as they could not measure how information obtained through the hacks influenced public opinion.

Mr Tillerson was speaking on the second day of confirmation hearings for Mr Trump’s Cabinet picks, which still need congressional approval.

He did not mention the conclusions reached by the intelligence community in his opening statement, but when questioned by Senator Marco Rubio, Mr Trump’s former rival for the Republican presidential nomination, he said he found the findings “clearly troubling”.

He also admitted that it was a “fair assumption” that President Vladimir Putin directed the cyber attack.

The former ExxonMobil chief executive has conducted extensive business with the Russian President, causing concern among critics of the incoming Trump administration, that already faces scrutiny for their relationship with the country.

In 2011, Mr Tillerson negotiated an energy partnership with Russia that Mr Putin valued at approximately $500bn (£409bn). The partnership resulted in Mr Tillerson receiving the Order of Friendship, Russia’s highest honour awarded to foreign nationals.

In pictures: Russian air strikes in Syria Show all 19 1 /19 In pictures: Russian air strikes in Syria In pictures: Russian air strikes in Syria Syrian boys cry following Russian air strikes on the rebel-held Fardous neighbourhood of the northern embattled Syrian city of Aleppo Getty In pictures: Russian air strikes in Syria Russian defense ministry spokesman Major General Igor Konashenkov speaks to the media in Moscow, Russia. Konashenkov strongly warned the United States against striking Syrian government forces and issued a thinly-veiled threat to use Russian air defense assets to protect them AP In pictures: Russian air strikes in Syria Syrians wait to receive treatment at a hospital following Russian air strikes on the rebel-held Fardous neighbourhood of the northern embattled Syrian city of Alepp Getty In pictures: Russian air strikes in Syria Russian Deputy Defense Minister Anatoly Antonov speaks at a briefing in the Defense Ministry in Moscow, Russia. Antonov said the Russian air strikes in Syria have killed about 35,000 militants, including about 2,700 residents of Russia AP In pictures: Russian air strikes in Syria Jameel Mustafa Habboush, receives oxygen from civil defence volunteers, known as the white helmets, as they rescue him from under the rubble of a building following Russian air strikes on the rebel-held Fardous neighbourhood of the northern embattled Syrian city of Aleppo Getty In pictures: Russian air strikes in Syria Civil defence members rest amidst rubble in a site hit by what activists said were airstrikes carried out by the Russian air force in the town of Douma, eastern Ghouta in Damascus, Syria Reuters In pictures: Russian air strikes in Syria A girl carrying a baby inspects damage in a site hit by what activists said were airstrikes carried out by the Russian air force in the town of Douma, eastern Ghouta in Damascus, Syria Reuters In pictures: Russian air strikes in Syria Civilians and civil defence members look for survivors at a site damaged after Russian air strikes on the Syrian rebel-held city of Idlib, Syria Reuters In pictures: Russian air strikes in Syria Civilians and civil defence members carry an injured woman on a stretcher at a site damaged after Russian air strikes on the Syrian rebel-held city of Idlib, Syria Reuters In pictures: Russian air strikes in Syria Volunteers from Syria Civil Defence, also known as the White Helmets, help civilians after Russia carried out its first airstrikes in Syria In pictures: Russian air strikes in Syria The aftermath of Russian airstrike in Talbiseh, Syria In pictures: Russian air strikes in Syria Smoke billows from buildings in Talbiseh, in Homs province, western Syria, after airstrikes by Russian warplanes AP In pictures: Russian air strikes in Syria Russian Air Forces carry out an air strike in the ISIS controlled Al-Raqqah Governorate. Russia's KAB-500s bombs completely destroy the Liwa al-Haqq command unit In pictures: Russian air strikes in Syria Caspian Flotilla of the Russian Navy firing Kalibr cruise missiles against remote Isis targets in Syria Â© TASS/ITAR-TASS Photo/Corbis In pictures: Russian air strikes in Syria Russia claimed it hit eight Isis targets, including a "terrorist HQ and co-ordination centre" that was completely destroyed In pictures: Russian air strikes in Syria A video grab taken from the footage made available on the Russian Defence Ministry's official website, purporting to show an airstrike in Syria In pictures: Russian air strikes in Syria A release from the Russian defence ministry purportedly showing targets in Syria being hit In pictures: Russian air strikes in Syria Russia launched air strikes in war-torn Syria, its first military engagement outside the former Soviet Union since the occupation of Afghanistan in 1979. Russian warplanes carried out strikes in three Syrian provinces along with regime aircraft as Putin seeks to steal US President Barack Obama's thunder by pushing a rival plan to defeat Isis militants in Syria In pictures: Russian air strikes in Syria Caspian Flotilla of the Russian Navy firing Kalibr cruise missiles against remote Isis targets in Syria, a thousand kilometres away. The targets include ammunition factories, ammunition and fuel depots, command centres, and training camps Â© TASS/ITAR-TASS Photo/Corbis

But ExxonMobil had to cease operations in the region in 2014, after US sanctions resulted from the illegal annexation of Crimea – which Mr Tillerson opposed at the time. The head of the oil giant’s Russian operations, Glenn Waller, said the company would return to the project once sanctions had been lifted.

Mr Tillerson said there should have been a military response to Russia in 2014, and their aggression toward the Ukraine resulted from an “absence of American leadership”.

“I’m advocating for responses that will deter and prevent further expansion of a bad actor’s behaviour,” he said.

“Sanctions are a powerful tool, and they’re an important tool.”

Heckler interrupts Tillerson'a confirmation hearing, shouting "I reject you"

But he stopped short of being overtly critical of Vladimir Putin – especially when it came to his actions in Syria – and refused to call him a war criminal.

“I would not use that term,” he said. “Those are very, very serious charges to make and I would want to have much more information before reaching a conclusion.”

Mr Rubio responded: “There’s so much information out there. It should not be hard to say that Vladimir Putin’s military has conducted war crimes in Aleppo.”

The Florida senator and former presidential candidate could throw a wrench in the President-elect's plan to place the oil executive in the highest foreign policy position in the US.

Should Mr Rubio decide to vote against Mr Tillerson, then the committee would deliver an unfavourable report to the Senate.

Only three Republican Senators, then, would need to break with the party and vote against Mr Tillerson to reject his nomination.

"I'm prepared to do what's right," Mr Rubio told reporters after the hearing, declining to give a definitive answer regarding his decision.

On the issue of climate change – a matter that the Obama administration has worked to tackle, resulting in a global agreement to slash carbon dioxide emissions – Mr Tillerson diverged from Mr Trump’s denial of the phenomenon and admitted that it existed. But he wrote off his company’s role in spreading disinformation to undermine the science behind global warming.

“The risk of climate change does exist, and the consequences could be serious enough that action should be taken,” he said. “Our ability to predict that effect is very limited [and the action nations should take] seems to be the largest area of debate existing in the public discourse.”

But when asked about the role of ExxonMobil throughout his 41 year career with the company, he dismissed the question.

Documents published by Inside Climate News, a Pulitzer Prize-winning nonprofit, indicate that Exxon knew about the impact of fossil fuels on the environment as early as 1982.