The leaders of France, UK also pledge cooperation on nuclear energy projects

Britain's Prime Minister Rishi Sunak and France's President Emmanuel Macron have had their first face-to-face talks, at the COP27 climate summit in Egypt, as the two countries try to improve relations strained by the issue of people smuggling across the English Channel.

During the summer Conservative Party leadership race, Sunak's predecessor Liz Truss infamously said "the jury was out" on whether France was a friend of the United Kingdom, and that she would judge Macron on "deeds not words", prompting much criticism.

Macron replied that Britain was "a friendly, strong and allied nation, regardless of its leaders, and sometimes in spite of its leaders", and when Sunak replaced Truss in Downing Street, Macron was one of the first world leaders he spoke to.

Since Britain left the European Union, the number of people crossing the Channel in small boats to arrive on its shores has risen dramatically, causing a political storm and also raising concerns about the health and safety of those attempting to cross, both on their way and also when they arrive.

The Manston immigration center in Kent, in southern England, has been filled way over capacity, with reports of outbreaks of serious disease, and counterterrorism police say the firebombing of another migrant center, in the port town of Dover, "meets the threshold for a terrorist incident".

Although Sunak did not come away with any firm agreements over the next course of action, he said he would "get a grip of this situation" and hoped to make a major announcement on progress before Christmas.

Before boarding his flight home, Sunak said the talks had given him "renewed confidence and optimism" over the issue, despite the lack of a clear timetable for what to do next. "Working together with our European partners, we can make a difference, grip this challenge of illegal migration and stop people coming illegally," he told reporters.

A statement issued by Macron's office backed up the optimistic tone, saying the pair had "agreed to remain in contact to advance coordination between their two countries in the face of the challenge of irregular migration".

In addition to their immigration discussion, Sunak and Macron also pledged to pursue what has been called "ambitious cooperation" in the field of nuclear energy, to deal with the threat posed by reduced fuel supplies caused by the conflict in Ukraine.

The Daily Telegraph newspaper reported that this could result in French state-owned energy company EDF taking joint control of the proposed new Sizewell C plant in Suffolk, in the east of England, pushing previous partner the China General Nuclear Power Corporation, or CGN, out of the picture.

The leaders of China and the UK met in October 2015, after which EDF and CGN agreed on a partnership for developments in the UK including Sizewell, a deal which EDF Chairman Jean-Bernard Levy called "a big step forward for EDF's 30 year partnership with our Chinese partner CGN … strongly supported by the governments of the UK, China and France".

Then CGN chairman He Yu said "entering the UK's nuclear market marks a new phase for CGN", and he called the move "a triple-win for the existing nuclear energy partnership between China, France and the UK".

However, Sino-British relations have since cooled and the National Security and Investment Act has been introduced. It is "a stand-alone statutory regime for government scrutiny of, and intervention in, acquisitions and investments for the purposes of protecting national security in the UK".