When asked how he got onto the White House grounds, Tran said, "I jumped the fence".
Secret Service searched the man's backpack as a precautionary measure and determined it didn't contain any hazardous material, the newspaper reported.
After the intruder's arrest and removal of the backpack by a bomb disposal unit, a search on White House grounds did not reveal another threat.
The incident is the first known security breach at the White House since Trump took office. Trump added that the security breach was "very sad". The incident happened just before midnight.
Tran confessed to jumping the fence of the White House.
Tran was also carrying two cans of Mace, a US passport, an Apple laptop and a book written by Trump, according to the complaint.
The man did not have a meeting with Trump, according to the Secret Service, and the president was subsequently briefed on the matter.
Tran made his first court appearance in Superior Court of the District of Columbia this afternoon on a charge of entering or remaining in restricted grounds while using or carrying a unsafe weapon.
The entrance where the man was arrested is near the part of the White House where the President resides. Tran wrote in the letter that he had been followed and that his phone and email were being monitored by others. The grounds of the presidential complex were also deemed safe.
In the most shocking case, Omar Gonzales, 42, made it all the way to the north portico doors of the White House while carrying a knife. That incident contributed to the resignation of Secret Service Director Julia Pierson. Webster then verified through the White House Joint Operations Center that Tran did not actually have an appointment and placed him under arrest on a charge of unlawful entry.