Sarkozy received 27 percent of the vote, and was edged out by Socialist Francois Hollande with 28 percent.
But far-right candidate Marine Le Pen finished a surprising third with more than 18 percent, the best showing for the anti-immigrant National Front party.
Sarkozy said Monday that National Front voters must be respected. "They have made a choice. They have expressed a choice. It is a vote of suffering, of crisis, why insult them? I tell them that I have heard them," he said. "I will take the consequences.''
Hollande says he will not seek out far-right voters. "I am not going to seek out voters from the extreme right, I will not try to seduce them. The far right has strong support at the moment and that is the fault of Nicolas Sarkozy," he stated. "But some voters voted for the far right because they are angry [at Sarkozy]. They are the voters who I want to hear from."
Hollande says he wants to unite what he calls a country divided by Sarkozy's failed policies. He also says he wants to boost taxes on millionaires.
Sarkozy remained upbeat about the second round, despite being the first incumbent to lose a first-round vote in modern French history. He said the moment of decision has arrived and he is better equipped than his Socialist competitor to guide France through the difficult challenges ahead.
Sarkozy challenged Hollande to three debates on social, economic and international issues before the May 6 runoff. But Hollande dismissed the offer as a desperate ploy by a candidate who knows he is in trouble.
