In what Reuters has said was "an apparent sign of support just three days before the first round of an uncertain presidential election", French presidential candidate Emmanuel Macron - and the market-friendly candidate preferred by Europe's establishment - spoke with former U.S. president Barack Obama on the phone on Thursday.

Quick to avoid the perception of yet another foreign interference (who can forget Obama's strong condemnation of the Brexit campaign last summer), in a statement from Kevin Lewis, spokesperson to President Barack Obama, he said that "an endorsement was not the purpose of the call, as President Obama is not making any formal endorsement in advance of the run-off election on Sunday." And yet, the optics certainly imply just that.

The full statement below:

"President Obama spoke on the phone to Emmanuel Macron this morning. President Obama appreciated the opportunity to hear from Mr. Macron about his campaign and the important upcoming presidential election in France, a country that President Obama remains deeply committed to as a close ally of the United States, and as a leader on behalf of liberal values in Europe and around the world. An endorsement was not the purpose of the call, as President Obama is not making any formal endorsement in advance of the run-off election on Sunday."

Macron said Obama wanted to exchange views about the French presidential campaign and that the ex-president had stressed how important the relationship between the two countries was.

Macron's party "En Marche!" said in a statement that "Emmanuel Macron warmly thanked Barack Obama for his friendly call."

In a separate statement, Obama's spokesman added: "an endorsement was not the purpose of the call, as President Obama is not making any formal endorsement in advance of the run-off." Macron is the only candidate so far to have said he has talked with Obama, a popular figure in France.