Six-time Olympic gold medallist Allyson Felix says "the fire is there" as she targets the 2020 Tokyo Olympics after missing out on a medal at the US National Championships.
Felix, 33, finished sixth in the 400m final in 51.94 seconds, behind winner Shakima Wimbley.
The Championships marked her return to racing for the first time in 13 months, after her daughter's birth in November,
Felix said this weekend had been a "stepping stone".
"I want to be back in the Olympics," said the 11-time world champion. "I want them more than anything. I want to go out on my terms.
"Being in this environment and being back in a final, it kind of got the juices flowing. It's going to be a lot easier going into next year and getting a full year of training."
She added: "This gave me a taste. The fire is there. I will be back next year."
Felix gave birth to daughter Camryn by emergency caesarean section, 32 weeks into her pregnancy in November.
The US Championships serve as trials for the World Championships in Doha, which start on 27 September and she could potentially be called-up for the 4x400m relay team.
"If I feel like I'm in good form to be able to help the team, yes," Felix said when asked if she would accept a World Championship spot. "If I'm not, I'll be a cheerleader."
Elsewhere, Michael Norman suffered a shock defeat as he finished second to Fred Kerley in the men's 400m. Kerley won in 43.64 seconds.
Norman, 21, ran a world leading 43.45 seconds in April - a time that has only been bettered by world record holder Wayde Van Niekerk, four-time Olympic champion Michael Johnson and Butch Reynolds. He also holds the world indoor record at 400m.