On 9 June, de Gaulle flew to London and met British Prime Minister Winston Churchill for the first time. It was thought that half a million men could be evacuated to French North Africa, provided the British and French navies and air forces coordinated their efforts. Either at this meeting or on 16 June, he urged Churchill in vain to throw more Royal Air Force (RAF) aircraft into the Battle of France, but conceded there and then that Churchill was right to refuse.