Surveys projecting a second-round clash between Macron and Le Pen have consistently shown the centrist candidate winning by a comfortable margin. "We must help him (Macron) as much as we can to ensure Le Pen is kept as low as possible", Valls told France Inter radio.
Macron came in second among Israelis, receiving 30.93% of the vote, and Le Pen was in third with 3.72%.
A total of 11 candidates campaigned in this year's race for the French presidency and the two leading candidates are set to face off in the runoff on May 7.
He said he would vote for his former economy minister, because he was best placed to unite the people of France.
Hollande said the far-right would "deeply divide France" at a time when the terror threat requires solidarity.
France has seen a series of attacks by Islamist militants in the past two years which have killed more than 230 people; only three days before Sunday's vote, a policeman was shot dead and two others were wounded in central Paris in an attack claimed by the Islamic State jihadist group.
"It's risk-on. The French presidential election was an obvious risk, and it now looks like, barring a shock, Macron will gallop ahead and the market will have its candidate in place, and that´s another hurdle overcome this year", said BNY Mellon currency strategist Neil Mellor, in London.
The two established political parties finished far out of the money, and Immanuel Macron, the new front-runner, is a banker who is the preferred candidate of the current Socialist president, Francois Hollande, who is so unpopular that he was the first president not to stand for re-election since World War II.
Canadian Lumber Industry Hits Back at `Unfair' Trump Tariffs
The president announced the decision during a gathering with conservative media outlets at the White House Monday evening. What comes next on softwood is a study of separate anti-dumping duties, followed by a final verdict by the U.S.
But in a surprise move on Monday - just one day after the first round vote - Ms Le Pen appeared to distance herself from the party.
Sunday's results were a stunning blow to France's traditional political class, with voters fleeing the ruling Socialists and conservative Republicans who have governed for the past half-century. "Now we are going to have one", the source added.
Choosing from inside the system is no longer an option.
On Monday, Le Pen announced a gambit created to help her do just that. "He is a hysterical, radical "Europeanist". He is for total open borders. He says there is no such thing as French culture.
"I'm not convinced that the French are willing to sign a blank cheque to Mr Macron", he said.
Both Macron and Le Pen campaigned as rebels who transcended the left-right divide.
Opinion polls indicate that the business-friendly Macron, who has never held elected office, will take at least 61 percent of the vote against Le Pen after two defeated rivals pledged to back him to thwart her eurosceptic, anti-immigrant platform. She made a bid for left-behind union members, the core of France's old left-wing alliance, by saying that she would protect their cherished social benefits by turning back the forces of globalization.
Comments