08/29/2014 12:12 EDT | Updated 10/29/2014 05:59 EDT

Tony Stewart says driver's death will 'affect my life forever'

In his first public appearance since he struck and killed a fellow driver, NASCAR star Tony Stewart said Friday that the crash will "affect my life forever."

Stewart, a three-time NASCAR champion, has not raced since his car hit Kevin Ward Jr. at an Aug. 9 sprint car event in upstate New York. Stewart pulled out of the NASCAR race at Watkins Glen the next morning, then skipped the races at Michigan and Bristol Motor Speedway.

"This is one of the toughest tragedies I've ever had to deal with," Stewart said Friday, speaking softly while reading from a sheet of paper. "This is something that will definitely affect my life forever. This is a sadness and a pain that I hope no one ever has to experience in their life."

"With that being said, the pain and the mourning that Kevin Ward's family is experiencing is something that I can't possibly imagine."

Stewart did not take questions from the assembled media, saying "there will be a day when I can sit here and answer the questions."

Stewart, who will return to NASCAR competition on Sunday night at Atlanta Motor Speedway, said "being back in car this week with my racing family will help me get through this difficult time."

Stewart-Haas Racing executive vice president Brett Frood said it was "100 pe rcent" Stewart's decision to race. He said Stewart is "emotional" but ready to return.

Stewart, who was described by police as "visibly shaken" the night of Ward's death, had been in seclusion ever since. Stewart-Haas Racing executive vice-president Brett Frood had said the team was putting no timetable on his return to the No. 14 Chevrolet and the emphasis was on giving Stewart time needed to get him "in a better place than he is."

Before Friday, Stewart's only comment since Ward's death was a statement the day after the crash in which he said "there aren't words to describe the sadness I feel about the accident that took the life of Kevin Ward Jr."

Ward had climbed from his car after it had spun while racing for position with Stewart. The 20-year-old walked down onto the racing surface waving his arms in an apparent attempt to confront Stewart.

Authorities said the first car to pass Ward had to swerve to miss hitting him. The front of Stewart's car then appeared to clear Ward, but Ward was struck by the right rear tire and hurtled through the air. He died of blunt force trauma.

It was not clear if the 43-year-old NASCAR superstar will be charged in Ward's death. Ontario County Sheriff Philip Povero has said investigators did not have any evidence to support criminal intent by Stewart. Povero said this week he has no new updates on where the investigation stands.

Meanwhile, Stewart will move forward with his career and attempt to salvage his season.

NASCAR released a statement Thursday saying that Stewart was eligible to return because he "has received all necessary clearances required to return to all racing activities."

Stewart, who has 48 career Cup wins in 542 starts, is one of the biggest stars in the garage. His peers have been protective of him as questions emerged in the aftermath of the crash, and it pained them that Stewart was grieving in private and had cut off communication with so many of them.

NASCAR rules state a driver must attempt to either qualify or race the car in every points-paying event to be eligible for the Chase for the Sprint Cup championship, unless a waiver is granted.

Since Ward's death, NASCAR has announced a rule that prohibits drivers from exiting from a crashed or disabled vehicle — unless it is on fire — until safety personnel arrive. Last week, Denny Hamlin crashed while leading at Bristol and stayed in his car until safety personnel arrived.

But Hamlin then exited his vehicle and angrily tossed a safety device at Kevin Harvick as he passed by moments later. He was not penalized.