It is a UFO for sure!
It's and Object.. that is flying... and can not be conclusively identified = UFO!
I however believe that it is not alien (per say) in nature. my money bet would be that it is an common aircraft that you have filmed. I am always sceptical of any filmed event that shows a flashing light similar to your video moving across the sky. It's too linear, too large, to unhidden, too commonly confused with man made stuff, etc.
Just my opinion.
But keep looking.