A Downing Street spokesperson said:
The Prime Minister spoke to NATO Secretary General Jens Stoltenberg this afternoon.
They discussed the continued importance of the Alliance as the bulwark of our defence, and agreed on the need for the Alliance to continue to evolve to be able to effectively counter the biggest threats of the day, in particular terrorism and cyber attacks.
The Prime Minister said she would be taking these messages to Washington later this week where she is expected to discuss NATO with President Trump.