Emmanuel Macron is visiting Calais amid reports that he is seeking to renegotiate Britain's role in dealing with migrants gathered at the French port.
Hundreds of asylum seekers hoping to cross the Channel remain in the area, more than a year after authorities dismantled the town's sprawling Jungle camp.
The French president was meeting Calais Mayor Natacha Bouchart and organisations working with migrants on Tuesday, just two days before talks with Prime Minister Theresa May.
Aid groups have labelled the visit a "political show", while organisation L'Auberge des Migrants said it has declined to meet Mr Macron "to show our profound disagreement with the upcoming immigration law".
One refugee called on the president to show "pity" for the plight of migrants in his policy.
It has been reported that France wants to secure an increase in Britain's financial contribution to the costs associated with the Calais migrant camps, where an estimated 700 people are living.
Senior French politicians are also said to be pressing the UK to receive more refugees from the region and lone children in particular.
Solenne Lecomte, from aid organisation La Cabine Juridique, called on Mr Macron to work with such groups to understand the reality of the situation and branded his visit a "political show".
Speaking at a press conference in Calais on Tuesday, she said: "If you are talking about migrants you need to have at least migrant organisations working with you.
"You can't just talk alone and decide alone."
She described conditions in the camp as "dreadful", with a lack of resources to support migrants.
"People are not stopping just because someone tells them they have to stop," she said.
"Unless someone moves the border it will be the same situation for a long time."
A 32-year-old refugee from Ethiopia, who has been living in the camp for six weeks, said the camps were a "disaster".
The man, who did not wish to be identified, said: "We are all here to pass the border to get into England.
"Daily life is just running after lorries, and it's not that easy. The borders are closed and there's too much control."
He added: "We are also confronting death and at the same time the violence of the police, which is really getting harder and harder.
"They beat you and they have no pity."
The man, who is hoping to reach Canada where he has family, said migrants were just "people looking for a future".
"I'm not expecting a lot but I just want to send a message to Mr Macron that we are humans and he is also human and he should have a little pity for us."
He added: "Mr Macron is never going to have time for us because we are just nobody for him.
"They call us illegal. I don't understand what that means.
"I've got a name, I've got an identity. So I'm not calling myself illegal."