NBC News Chairman Andy Lack said in a note to employees on Friday that the network takes sexual misconduct allegations against news veteran Tom Brokaw "very seriously," promising the network will "act on them quickly and decisively when the facts dictate."

"As you have all seen now in reports from last night, there are allegations against Tom Brokaw, made by a former NBC News journalist, which Tom emphatically denies," Lack wrote. "As we've shown, we take allegations such as these very seriously, and act on them quickly and decisively when the facts dictate."

Brokaw, 78, staunchly denied the claims by two women, including a former employee, that he made unwanted advances more than 20 years ago, saying in a lengthy email obtained by the Los Angeles Times and Hollywood Reporter that he was "ambushed" by the report.

He accused one of his accusers, former NBC News correspondent Linda Vester, of being part of the "Look at Me" movement rather than the "Me Too" movement.

"I was ambushed and then perp walked across the pages of The Washington Post and Variety as an avatar of male misogyny, taken to the guillotine and stripped of any honor and achievement I had earned in more than a half century of journalism and citizenship," Brokaw wrote.

"What was her goal?" he asked of Vester. "Hard to believe it wasn't much more Look at Me than Me:Too," he wrote, referring to the movement against sexual harassment and assault.

"I am angry, hurt and unmoored from what I thought would be the final passage of my life and career, a mix of written and broadcast journalism, philanthropy and participation in environmental and social causes that have always given extra meaning to my life," he added.

Vester's attorney said Friday after Brokaw's email was made public that she stands by her claims.

Lack also noted that a review into former "Today" show anchor Matt Lauer, who was ousted from the network in November amid sexual harassment allegations, is "nearing its conclusion." The network also launched a review of the company culture following the allegations against Lauer.

He promised that "findings and further steps" will be given to employees as soon as next week.

"Once again, our highest priority is to ensure we have a workplace environment where everyone feels safe and protected," Lack wrote. "We are absolutely committed to making this a reality - there can be no exception."

Lack added that 1,600 employees have completed "mandatory in-person workplace training sessions" and expects to "have all 2,000 of our employees trained by end of summer."

Brokaw began his career at NBC 52 years ago, and was the anchor of the "NBC Nightly News" from 1982 to 2004.

His title is currently NBC News anchor emeritus.