Buttler says committed to learning from errors as England struggle
England crashed out of the 50-over World Cup last month, before suffering Twenty20 and one-day international series defeats at the hands of West Indies.
Asked if he had doubts over his ability to lead the side, Buttler told reporters: "Not really. I've had some low moments, for sure. It was a huge disappointment in my career, that World Cup that's just gone.
"But after you let the dust settle there's huge motivation and determination to have another crack and just keep going. That desire still burns strongly.
"It's important you learn and get better and try not to make the same mistakes. It's the same for my own game as a player, I want to just get better and better and I feel like I've still got higher levels to reach."
Following Thursday's T20 series defeat to West Indies, England coach Matthew Mott said the side had taken valuable lessons ahead of next year's Twenty20 World Cup.
Buttler echoed Mott's words, saying: "There's lots to look forward to next year with the World Cup and I thought we played some really good cricket for the majority of the series.
"We all wanted to win the series and it's hard to say when you've lost, but I think we've found out some good things. Obviously some players have stood up and done really well.
"We've had five games out here in the Caribbean and had a really good look at what conditions will be like for the World Cup only six months away. So yeah, it's been a good series."
England will play just one four-match series against Pakistan in May before defending their T20 World Cup title in the United States and West Indies in June.