Mr Sunak and French President Emmanuel Macron will meet at the Elysee Palace alongside senior ministers in the first Anglo-French summit for five years.

The UK wants to look at boosting police patrols on French beaches, from where many small boat crossings leave.

A deal on returning migrants arriving in the UK to France is not expected.

Earlier this week Mr Sunak unveiled his plans to deter people from making the crossing.

Under the plans, anyone found to have entered the country illegally would not only be removed from the UK within 28 days, but also be blocked from returning or claiming British citizenship in future.

Those arriving on the UK's beaches would either be returned to their home country, or another "safe third country" like Rwanda.

It is thought the UK and French leaders will meet for around half an hour.

The British government believes money sent to France to step up patrols has been value for money and wants to go further.

The prime minister's official spokesman said: "We want to do more and we also believe France wants to stop these illegal gangs exploiting people."

"Certainly we are going in there with an ambition to go further on stopping the boats making these dangerous crossings," the spokesman added.

But both London and Paris acknowledge there will not be an agreement where France takes back migrants who have reached the UK.

The French government is thought to prefer a deal between the UK and the European Union, something of a frustration to British diplomats who would like to see quicker action.

"We want a EU-UK returns agreement and will push that forward," the spokesman said.

"But it is equally important that there is work on the ground right now to stop the crossings we are seeing even in these winter months."

"At this stage, and due to Brexit, there is no readmission agreement between France and the United Kingdom," a French government source said.

Labour said the absence of a new agreement to return migrants to France was a "total failure."

The British government feels the relationship with their opposite numbers in Paris on this issue has improved significantly in the last couple of years.

But Downing Street's desire to "to make the small boat route across the Channel unviable" is a bold ambition, given the numbers proving it to be the opposite have continued to rocket.

More than 45,000 people entered the UK via Channel crossings last year, up from about 300 in 2018.

So far this year, around 3,000 people have arrived on small boats, but the two governments claim their joint work has stopped a similar number from embarking on the journey.

An announcement on deepening co-operation on the issue is expected, rather than a big breakthrough.

The joint work the two countries do on it remains politically sensitive, as our Europe editor Katya Adler writes here.

Mr Sunak said: "From tackling the scourge of illegal migration to driving investment in one another's economies the work we do together improves the lives of each and every person in our countries.

"Beyond that, the UK and France also have a privileged role as defenders of European and global security."

Officials point out that both the UK and France are nuclear powers, members of the G7, G20 and the Nato defence alliance and permanent members of the United Nations Security Council.

Brexit has been something of a stone in the shoe of the relationship between the UK and France in recent years.

But diplomats believe the deal between the UK and the European Union on Brexit arrangements in Northern Ireland creates a much better atmosphere between the two countries.

And both London and Paris are keen to emphasise their closeness on so many other issues, not least Ukraine.

The prime minister and the president will host a news conference on Friday afternoon and issue a joint statement.

It is a month of particularly intense activity between the two countries - as King Charles and the Queen Consort will be in France in a few weeks.

Next year marks the 120th anniversary of the Entente Cordiale, which put an end to centuries of rivalry between the two countries.