Nearly 1,000 people have been taken into custody nationwide.
About 8,000 police officers were on the ground in Paris - almost twice as many as last week. At least three police officers were also hurt. The French yellow vest protest movement is crossing borders, with demonstrations planned in neighboring Belgium and in the Netherlands.
A young man was suffered a serious hand injury during clashes with police in the southwestern city of Bordeaux, apparently by an anti-riot grenade.
An interior ministry official told AFP that authorities were bracing for "significant violence" Saturday, based on indications that protesters on both the far right and far left are planning to converge on Paris.
"The dialogue has begun", Philippe said. "It is now necessary to rebuild the national unity".
But numerous demonstrators insisted they wanted no violence.
Large groups of people were heading to eastern Paris, where a march against climate change was under way.
There have been a number of confrontations in the capital. The city subway system was shut down in the center of town.
About 89,000 security forces were deployed across the country, including military, local police, and special police to contain the estimated 125,000 yellow vest protesters.
His tweets came in the middle of UN climate talks in Poland, where almost 200 nations have gathered to agree on a universal rulebook to make good on promises they signed up to in the 2015 Paris climate deal to cap global warming at well under two degrees Celsius (3.6 Fahrenheit).
Shops, museums, metro stations and the Tour Eiffel were closed, while top-flight football matches and music shows had already been cancelled.
The French government is relieved that its worst forebodings about the protests did not come to pass.
Out of the media spotlight, Macron met Friday night with riot police being deployed in Paris Saturday.
It is a relief for President Macron - but not much more.
But the yellow vests, some of whom who have become increasingly radicalised, are holding out for more.
"They have some time to prepare", Stapts said.
Trump's comments appearing to sympathize with unsafe protesters in a friendly country went against longstanding precedent for USA presidents.
To Macron, this means not only Macron encouraging start up businesses in France, but he wants to turn France into "a nation that thinks and moves like a startup", as he described it shortly after his election in June 2017.
They were clad in yellow hi-vis vests, the symbol of a movement that began as a protest against rises in tax on diesel and has quickly turned into a wider expression of discontent with the government. About 100 people were arrested in the capital Brussels. The protesters in Brussels threw paving stones, road signs, fireworks, flares and other objects at police and about 100 were detained, many for carrying unsafe objects.
In some cases, yellow vests joined the demonstrations.
The "gilets jaunes" protesters are so-called because they have taken to the streets wearing the high-visibility yellow clothing that is required to be carried in every vehicle by French law.
Its core aim, to highlight the economic frustration and political distrust of poorer working families, still has widespread support.
That decision is deeply unpopular with protesters and, along with a string of comments deemed insensitive to ordinary workers, has led critics to label Macron a "president of the rich".
What has the government conceded?
Last week the French government announced they were scrapping the fuel increases and has frozen electricity and gas prices for 2019.
Some protesters called for support for a borderless European Union, while others demanded Frexit, or a French exit from the bloc.
An immediate increase in the minimum wage and pension benefits has also been a rallying cry.
"We're asking him to meet us to negotiate on spending power, which is what underpins all this anger", Mr Cauchy said.