US has - had technology at its disposal for a while the aliens only had contact. US In the 50s let its allies in on the act as well as the USSR - kennedy came close to disclosure ( why do u think apollo was pushed hard) to gather far side lunar evidence of ET having a base on the moons far side.
Apollo 11 images were airbrushed before public realise. Even the director of photography has come out on the public record to admit this ( the director of photography who had oversight at NASA Of all the apollo mission images)
The process is now being moved through the UN ( see UN secret meeting febuary this year) where major nations are being kept up to date on a disclosure plan that wil yeield public ET contact in 2017
