It looks like the suspect was admitted to the United States under the Obama administration per the DOJ:
On Wednesday, the Department of Justice announced that a Syrian refugee has been arrested for allegedly scheming to attack a Pittsburgh church, the Legacy International Worship Center, "to support the cause of ISIS and to inspire other ISIS supporters in the United States."
The suspect's name was withheld by this media outlet based on a policy of not publicizing the name. It is unclear how close the suspect was from carrying out the attack.
According to the complaint and information provided to the FBI by the Department of Homeland Security, (the suspect) was born in Daraa, Syria, and was admitted to the United States as a refugee on Aug. 1, 2016.
In furtherance of the plot to bomb the Church, in May 2019, (the suspect) distributed multiple instructional documents related to the construction and use of explosives and improvised explosive devices (IEDs) to an individual (the suspect) believed to be a fellow ISIS supporter, but who was in fact an FBI employee. (The suspect) distributed these documents with the intent that the information be used in the assembly of a destructive device and in furtherance of conducting an attack in support of ISIS. In or around June 2019, (the suspect) purchased several items with the belief that they were necessary to assemble a destructive device and with the intention that they be used to construct the explosives that would be detonated in the vicinity of the Church.
In planning the attack, (the suspect) used multiple social networking and mobile messenger applications to communicate with an individual whom he believed to be a fellow ISIS supporter. During his communications, (the suspect) stated his support for ISIS, and his desire to answer the call for jihad or travel to conduct jihad. (The suspect) also distributed propaganda materials, offered to provide potential targets in the Pittsburgh area, requested a weapon with a silencer, and recorded a video of himself pledging an oath of allegiance to the leader of ISIS, Abu Bakr Al-Baghdadi.