Jenson Button said he was frustrated by backmarkers as he tried to chase down Sebastian Vettel at the end of the Singapore Grand Prix.
The McLaren driver was caught behind traffic when the race restarted after the safety car, then encountered a battling group in the closing stages as well while gaining on Vettel.
"I can understand that it is difficult to move over here, and most people were fighting out there, but they have to respect that the cars that are lapping them are lapping them for a reason – because they are faster and battling for position," said Button.
"I got stuck behind [Kamui] Kobayashi and lost a lap [of chasing], and the Williams were fighting among themselves."
Button cut Vettel's lead – which had got up to 13 seconds – down to 1.7sec by the flag, and said he had been able to unleash the McLaren's full pace in the final stint after saving fuel earlier in the race.
"In the last stint I was able to drive as fast as I could and put 12 qualifying laps together, took a lot of risks, enjoyed it," said Button. "I said coming here the aim was to win the race so we had to have a go, but had to settle for second in the end.
"Overall, our pace was good today – but we cannot challenge Seb and Red Bull. Second best we could be, this is something to build on. We know we are not as quick at the moment, we know we need to improve if we want to fight for wins in the next five races."