Rubio grills Tillerson over Russia's role in Syria

US President-elect Donald Trump's pick for secretary of state, Rex Tillerson, was grilled on his ties to Vladimir Putin during his confirmation hearing on Wednesday, as he refused to call the Russian leader a "war criminal" for Moscow's actions in Syria.

Tillerson, the longtime chief of ExxonMobil who had extensive business dealings in Russia, faced sharp questioning from the Republican of Florida, Senator Marco Rubio, over his unwillingness to criticise Putin.

"We are not likely to ever be friends" with Russia, Tillerson said.

Vladimir Putin awarded Tillerson the Russian Order of Friendship in 2014.

When asked whether he would call Putin a "war criminal", Tillerson said he would not use that term, stating that he would "wait until he sees detailed intelligence before making that decision".

Rubio replied: "Let me describe the situation in Aleppo and perhaps that will help you reach that conclusion. In Aleppo, Mr Putin has directed his military to conduct a devastating campaign.

"He's targeted schools, markets, not just assisting the Syrians in doing it. His military has targeted schools and markets and other civilian infrastructure that resulted in the death of thousands of civilians."

Tillerson said Russia's targeted bombing in the Syrian city of Aleppo "is not acceptable behaviour" but declined to flatly say that Moscow was guilty of war crimes.

"It should not be hard to say Vladimir Putin's army has committed war crimes in Aleppo," Rubio told him, to which Tillerson replied: "I look forward to being fully informed."

The senator replied: "None of this is classified. These people are dead."

Close ties

Faced with the pointed questions from Democratic and Republican senators, Tillerson sought to allay fears that either he or Trump would go easy on Moscow. But in a surprising revelation, he conceded that he hadn't yet discussed details with Trump about his ideas for a Russia policy.

His ties to Russia have faced scrutiny. Until he stepped down from ExxonMobil on New Year's Eve, Tillerson was also director of Exxon Neftegas, an affiliate that operates the Sakhalin-1 field in Russia's Far East.

The US parent firm was chasing greater investments in Russia, including Arctic fields, and Tillerson was a familiar and popular figure in Moscow, winning his medal from Putin in 2012.

This made ExxonMobil under Tillerson a staunch opponent of US and international sanctions against Russia for its aggressive behaviour in Ukraine, where it annexed the Crimea region.

But on Wednesday, Tillerson admitted Russia had taken "illegal action" with respect to Crimea.