The widow to Pulse nightclub shooter Omar Mateen has said that she wished she had been 'more truthful' with agents about his early warning signs.

'I wish I had done the right thing but my fear held me back,' Noor Salman said.

Her expression of remorse came just days after Mateen mass shot 49 people and wounding dozens in 2016 inside the Pulse nightclub in Orlando, Florida.

Salman (left), shown with, Omar Mateen (right) - she said on Monday that fear prevented her from telling police about his murderous intentions

Omar Mateen mass murdered 49 people and wounding dozens more inside the Pulse nightclub in Orlando, in 2016

Family members of Noor Salman arrived to federal court in Orlando on the morning that her trial began

It was one of at least three instances where Salman - who is on trial for aiding and abetting Mateen - allegedly spoke to police about some of the 'red flag' warning signs she noticed in the weeks and months leading up to the massacre, nypost.com reported.

Salman is accused of providing material support of a foreign terror organization and obstruction of justice. If convicted as charged, she faces up to life in prison.

Salman first claimed Mateen (pictured) acted without her knowledge. Later she acknowledged that she knew Mateen had bought an assault rifle and was watching ISIS recruitment videos

Prosecutors are continuing to build their case against Salman, orlandosentinel.com reported, after jurors on Monday heard testimony from an FBI agent who said she admitted knowing in advance that her husband was planning a massacre.

Special Agent Ricardo Enriquez was the only witness to testify in the trial Monday, spending hours on the witness stand as he described questioning Salman on the morning of the June 12, 2016, attack.

Enriquez transcribed her statements and recounted them in court Monday, nypost.com said.

'I am sorry for what happened,' Salman said. 'I was in denial because I could not believe that the father of my child would do this.'

The defendant, 31, claimed that one of the reasons she didn't speak up about her husband's plans was that she didn't want her in-laws to 'hate' her.

'I wish I'd go back and tell his family and the police what he was going to do,' she said, noting how Mateen regularly viewed Islamic State beheading videos and talked about being a terrorist.

'What would make people more upset, an attack at Disney or a nightclub?' Salman recalled her husband asking.

'I saw this as a 'green light' for (Mateen) to do great violence,' she said in her statement. 'I knew he was going to do something.'

Enriquez told jurors that Salman initially tried to claim she wasn't aware of any attack plans or warning signs, but said that her story eventually changed after being questioned further.

'I said, 'You know Noor, I realize that you knew what was going on. You knew,' Enriquez testified. 'She said, 'No I didn't.'

Salman was indicted on two charges: obstruction of justice for alleged false statements to federal investigators, and aiding and abetting Mateen in his attempt to provide material support to a terrorist organization

Christopher Leinonen (R) with his boyfriend Juan Guerrero, 22, who were both killed in the massacre

Christine Leinonen, mother of Pulse victim Drew Leinonen, became emotional speaking at a press conference outside the U.S. Federal courthouse in Orlando about the Noor Salman trial Wednesday, March 14, 2018

In a court sketch, widow Salman is shown next to her defense attorney Linda Moreno

The FBI agent told her to re-read her three statements to police — which she initialed and approved — and pressed her again.

'She began to cry, and said, 'I knew,' remembered Enriquez.

But Salman's lawyer, Linda Moreno, said in her opening statements that FBI investigators had bullied her into 'adopting their narrative' after 11 hours of interrogation.

She pointed out how no audio or video recordings were taken during the conversations with agents.

'Omar Mateen is a monster,' Moreno said. 'Noor Salman is a mother, not a monster. Her only sin is she married a monster.'