(CNN) The first thing President Donald Trump raised with Russian President Vladimir Putin in their meeting Friday at the G20 in Germany was Russia's interference in the 2016 election.

That's according to Secretary of State Rex Tillerson, who was in the meeting. "They had a very robust and lengthy exchange on the subject," he told reporters afterward. "The president pressed President Putin on more than one occasion regarding Russian involvement. President Putin denied such involvement as I think he has in the past."

Bringing up Russia's role in the election is an interesting strategy by Trump -- particularly given that White House officials had signaled in the run-up to Friday's meeting with Putin that the president might not raise the issue of election interference.

It's particularly odd given that less than 36 hours before Trump, according to Tillerson, "pressed" Putin on the meddling in the 2016 election, he was decidedly skeptical about the idea that Russia was fully to blame.

JUST WATCHED Trump: Russia 'and others' meddled in election Replay More Videos ... MUST WATCH Trump: Russia 'and others' meddled in election 03:17

"I think it very well could be Russia but I think it could very well have been other countries," Trump said Thursday at a press conference with Polish President Andrzej Duda. "I think a lot of people interfere."

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