A Downing Street spokesperson said:
The Prime Minister called the US President-elect this afternoon as part of establishing a regular dialogue between both of them.
They discussed how the President-elect’s transition plans were progressing and agreed that their teams should continue to build close relationships through this period, including with a meeting of their national security advisers in the United States before Christmas.
They discussed NATO, agreeing on the importance of the Alliance, the need for more NATO members to meet the target of spending 2% of GDP and the role that NATO can play in addressing diverse threats.
They agreed to stay in close touch and to meet at the earliest possible opportunity.