PARIS, March 10 (Reuters) – Britain will pay France around 480 million pounds ($577 million) over three years to try to stop migrants travelling in small boats across the Channel as the two allies on Friday took a major step to end years of bickering in the post-Brexit era. At a summit designed to rebuild ties, French President Emmanuel Macron greeted British Prime Minister Rishi Sunak with smiles and mutual back-slapping before they agreed to work more closely together. Describing it as a “moment to reconnect”, Macron told a joint news conference that relations had been strained by Britain’s departure from the European Union. Sunak said the time had come for a new relationship, an “entente renewed”, a reference to the Entente Cordiale of the early 20th century that had smoothed over diplomatic relations between the European powerhouses. “If we are honest the relationship between our two countries has had its challenges in recent years,” Sunak said. “Today we have taken cooperation to an unprecedented level.” The two agreed to move forward on nuclear energy cooperation, reaffirmed their backing for Ukraine and vowed to strengthen inter-operability of their military forces, including through the development of future missiles and air defence systems. But for Sunak, migration was the focus as he looks to tout the deal as another achievement after agreeing new terms with Brussels on Northern Ireland in February.