By Sabine Siebold ANKARA, July 8 (Reuters) - President Donald Trump told NATO allies he wanted to keep the United States in the alliance at a leaders' meeting in Ankara on Wednesday, a source familiar with the talks told Reuters. Inside the closed summit meeting, he also said the U.S. was prepared to continue selling weapons to allies no matter how they were put to use, the source said, requesting anonymity. The source quoted Trump as having told NATO leaders: "We want to remain with you".