Following US President Donald Trump's declaration that both a two-state or a single-state solution in Israel-Palestine might be acceptable at a joint press conference with Israeli Prime Minister Benjamin Netanyahu, Ayrault raised the question with Tillerson on the sidelines of a G20 conference in Bonn on Thursday.
"I found there was a little more clarification even if I found that on the Israeli-Palestinian question it remains very confused and worrying," he told the press afterwards.
France remains committed to the two-state solution, he said, and "the other option raised by Mr Tillerson is not realistic and is not fair or even-handed".
Iran nuclear deal
Paris also has differences with Washington over the 2015 agreement with Iran that lifted sanctions in return for guarantees that Tehran would only develop nuclear power for civilian purposes.
During the US presidential campaign Trump promised to rip up the deal, describing it as "stupid".
"I felt there was a question mark" over the accord, Ayrault said after meeting Tillerson. "For France there is no question of starting afresh the hard-won agreement."
"I didn't leave any such impression," Tillerson said before a meeting with the Argentinian foreign minister, when asked about Ayrault's remarks.
The French foreign minister did say that he had been given a "clearer" answer on the Trump administration's position on lifting sanctions on Russia over the Ukraine conflict, implying that Washington agreed that suspension would be condition on the implementation of the Minsk agreement, which stipulates that fighting must cease and heavy weapons withdrawn from the frontline.
Ayrault raps Assad 'cynicism'
Also on Thursday Ayrault accused Bashar al-Assad of cynicism and cruelty, following an interview the Syrian president gave to French media.
Assad accused France of "supporting terrorism from day one" of the civil war in his country.
"I don't know how to describe this statement, unless it is as absolute horror," Ayrault said.
France is totally committed to a political solution in Syria and supports next week's negotiations in Geneva, he said.
"Propaganda, cynicism and cruelty will not make us give up," the minister added.