A man arrested in Whitehall with three knives last year told police he was there to send a message to the UK's "hierarchy", the Old Bailey has heard.
Khalid Ali's comments, made during police interviews after his arrest, were read to the jury at his trial.
Mr Ali said he had not intended to kill anybody - and that the knives were for his "protection".
He has pleaded not guilty to possessing explosives overseas and preparing an act of terrorism in the UK.
Thursday's court hearing began with the jury being shown close-up video footage of Mr Ali, from Edmonton, north London, being arrested in Parliament Street by heavily armed officers on 27 April 2017.
Three new Sabatier knives were removed from his pockets and waistband.
CCTV footage from earlier that day showed him buying the knives at a Wilko store in west London and then travelling to Westminster via the underground network.
That night, in interviews at Southwark police station, Mr Ali told police officers that he was there to defend himself and his fellow Muslims, the court heard.
Transcripts of the interviews, read to jurors, record the defendant telling detectives: "If you thought that Trump guy is bad, letting off nukes, or that Kim guy in Korea, that's nothing, that's baby stuff to what's about to take place.
"You thought Bin Laden was bad enough, Bin Laden, that's nothing."
He told officers: "It is clear that there is a war on Islam," adding: "I would describe myself as a Mujahid."
But he said, however, he had no intention of killing police officers, the military or MPs.
He said he was there to deliver a message to what he called "those who are running the country", and the knives were to defend himself.
The trial continues.