Emmanuel Macron has held off a challenge from far-right leader Marine Le Pen to retain the French presidency, according to projected results from French polling agencies.

Macron, the centrist incumbent, is projected to get 57 percent to 58.5 percent of the vote in Sunday's second-round runoff, compared with 41.5 percent to 43 percent for Le Pen, his nationalist rival. 

If the projections are accurate, Macron will triumph decisively, although by a smaller margin than in 2017, when he won by more than 30 percentage points to became France's youngest president.  

While she fell short of the Élysée Palace again in her third presidential run, Le Pen still looks to have secured the most votes ever for a French far-right candidate. 

In a victory speech at Paris' Champ de Mars, Macron thanked his supporters and promised a more "independent France" and "stronger Europe."

“I also know that many of our compatriots voted for me today, not to support the ideas I hold but to block those of the extreme right," he said.  

"And I want to thank them here and tell them that I am aware that this vote binds me for the years to come." 

European leaders from Brussels to London and beyond, who may have feared a Le Pen win would upend the continent's post-war order, swiftly congratulated Macron on his re-election.