One of three men accused of conspiring to join the Islamic State admitted Friday that secret recordings captured his talk of getting martyred and helping to send fighters into the United States, but dismissed it as empty boasting.

Under questioning from a federal prosecutor, Guled Omar identified his voice in tape-recorded statements. But Omar testified Friday that what he said on the tapes recorded by a paid FBI informant months before his April 2015 arrest wasn't true.

"I was trying to sound like a big, bad guy who knows what he's doing," Omar later told his attorney, Glenn Bruder.

Omar is the only defendant to testify in the trial, which finished its third week at the Minneapolis federal courthouse. Omar, 21; Abdirahman Daud, 22, and Mohamed Farah, 22, were indicted last year on charges that include conspiracy to provide material support to the Islamic State in Iraq and the Levant (ISIL) and to commit murder abroad. The latter charge carries a potential life sentence. Six others have pleaded guilty.

Omar first took the witness stand Thursday, and his testimony continued into Friday afternoon before both sides rested their cases. Closing arguments in the trial will start Tuesday and may extend into Wednesday.

Under cross-examination by Assistant U.S. Attorney Andrew Winter, Omar at times asked to have difficult-to-hear audiotapes replayed before confirming his role in the conversations. He also said he had trouble recalling some discussions because both he and the informant, Abdirahman Bashiir, had smoked marijuana together.

Omar's statements recorded by Bashiir in early 2015 included remarks that he would kill security officials at the Turkish border with Syria — "Once I'm there, it's do or die" — and musings over whether to bring a gun on an attempt first to cross into Mexico, "just in case they try to grab you."

The final tape Winter replayed Friday was of Omar saying that the group could one day share its route to Mexico with ISIL so it could send fighters into the U.S. to commit attacks.

"They'll do crazy damage," he said on the tape. "Wallah, we have a big opportunity."

"Those are your words aren't they, Mr. Omar?" Winter asked.

"Yes."

"No further questions."

Testimony and secretly recorded conversations made in early 2015 by Bashiir, a co-conspirator turned paid informant, have been at the heart of the government's case.

On Thursday, Omar disputed allegations that a series of failed travel attempts between 2012 and 2014 were efforts to join ISIL or Al-Shabab, the latter counting his older brother Ahmed among its ranks.

But on Friday, Winter played back March 2015 recordings made after Bashiir told Omar he had found a source who could get the group fake passports they could use to cross into Mexico and fly to Turkey. On the tape, Omar recalled a May 2014 road trip planned with Bashiir and Yusuf Jama — who soon after joined and died fighting for ISIL — that Omar's family members foiled. Of the trip, Omar said, "We would have made it because we would have found something like this guy."

Omar previously testified that the trip was to be a reward to himself for a good first year of college. But on Friday, Winter displayed a copy of Omar's academic transcript from Minneapolis Community and Technical College, which featured an F in macroeconomics, several withdrawals and one B in beginning Arabic.

"Isn't it true that the only reason you would go to school was to learn Arabic and get $5,000 to go to Syria?" Winter asked, referencing allegations that Omar tried to use financial aid money to finance his travel.

"No," Omar said. "Who said that?"

Encrypted chats

Winter also asked Omar about his friend Abdi Nur, the only one of 10 men charged to have made it overseas to join ISIL. Omar acknowledged keeping in touch with Nur using messaging apps he believed were encrypted.

"Because talking to an ISIL fighter could be bad, right?" Winter asked.

"Yes," Omar said. "It could make you look bad."

Omar's testimony was a departure from his first several hours on the stand Thursday, which was marked by animated retellings of events and a tearful recollection of how his brother's disappearance affected the family.

Next week, jurors will be handed the same tapes Omar and Winter reviewed, asked to decide whether they include evidence Omar and his co-defendants plotted to wage jihad abroad or tried to put on a tough face among friends.

"I didn't know how to flat out say, 'No, I don't want to go with you guys, and I don't think you guys should go either,' " Omar said.

Twitter: @smontemayor