UFO exists and were here for a long time. They have many varieties. They are very carefull in interacting with us. When humans are ready then governments and they will reveal themselves and their goals visiting earth.
The main reasons they are kept secret is cause of their medical technology (not propulsion tech) will make the world medical and food industry disrupted cause in reality deseases are engineered, sickness are making countries rich.
RE: RT News: 3 People Assassinated from Dr. Steven Greer's UFO/ET Research & Disclosure Group That Presented The World With Around 1000 Ranking Whistleblowers