EXCLUSIVE: Orlando Bloom Says Fatherhood Gave Him a 'New Sense of Responsibility'

The star opened up about how his 5-year-old son, Flynn, has made him more compassionate and praised girlfriend Katy Perry for her work with UNICEF.

Orlando Bloom is opening up about the one thing in the world that's changed his life the most: His 5-year-old son, Flynn.

The Pirates of the Caribbean star spoke with ET on the red carpet at UNICEF's 70th Anniversary Event at the United Nations Headquarters in New York City on Monday, where he opened up about how fatherhood completely reshaped his outlook on the world.

"Being a father, you know, you kind of have a new sense of responsibility," said Bloom, 39, adding that his "level of compassion" has grown since he and ex-wife Miranda Kerr welcomed Flynn in January 2011.

WATCH: Miranda Kerr Talks Co-Parenting With Ex Orlando Bloom: 'We Wanted to Be Close as a Family'

Because of this, his appreciation for UNICEF and their international charitable efforts has only grown. "I've seen the work that it does to actually make a difference in communities around the world and I couldn't be more honored to be a part of it and to celebrate 70 years tonight," Bloom said.

Bloom also marveled at the opportunity he's been given to work with the organization alongside his girlfriend, Katy Perry. And the star had nothing but praise and pride for what the "Roar" singer has accomplished in her time with UNICEF.

"She's amazing, you know, I'm super proud of the work that she does," Bloom shared. "She's a voice that speaks to so many and it's remarkable to see her champion this cause, [and] it's amazing that we happen to do this together."

WATCH: Katy Perry Opens Up About Boyfriend Orlando Bloom: 'We've Taught Each Other a Lot'

Recently, Perry was honored at the annual UNICEF Snowflake Ball in New York City, where the songstress spoke with ET about what it meant for her to have Bloom by her side on the special night.

"He's been a UNICEF ambassador for over 10 years and I've only been [for] a few years, so he's kind of shown me some of the ropes," she shared. "Everyone is a teacher in a relationship, that's how I see it now, [and] we've taught each other a lot." Check out the video below to hear more.

Additional Reporting By Rande Iaboni