Here is how Ultron, Riptide and Victor Creed kidnap the president in G-Merl's Eternal Quest.
(we see the president of the United States working on some paperwork)
President: This is worse than homework.
(suddenly, everything shakes and a helicopter appears)
President: What the?!
Riptide:(jumps out with Victor Creed)
(Ultron Sentries transform from attack drones, but do it like the KSI robots)
Victor Creed: Mr. President. Our boss wants you to help us.
President: Why should I go with you?!(prepares to grab a gun under his desk)
Ultron:(transforms from the helicopter) Because, you'll do it if you're own life depended on it.(takes out an injection gun) Disobey me, everyone in the White House dies.(injects a nano bomb into the President's neck)
President: What do you want from me?
Ultron: I want to know where the Sentinel prototypes and the advanced ones were hidden. And as the president, you know where they were hidden.
(realizing he had no choice, he agreed in return for his freedom)