Lewis Hamilton dedicated his sixth Formula One title to the late Niki Lauda and vowed to continue making his "incredible friend and mentor" proud.

Austrian F1 legend Lauda, who had served as Mercedes' non-executive chairman since 2012, died in May at the age of 70.

Lauda played a key role in bringing Hamilton to Mercedes and the Briton said his 2019 title triumph was for the three-time F1 champion.

"Six World Championships!! I can't begin to describe this feeling, but it's one I'll never forget." Hamilton posted on Twitter on Monday after a second-placed finish at the United States Grand Prix took him within one title of Michael Schumacher's record tally.

"As a kid growing up in Stevenage, it was a wish to win an F1 race and a dream to win a Championship, so to be standing here representing my country, is such an incredible honour and beyond what I could ever have imagined.

"If just one kids seems me standing here and decides to follow their dream, no matter what it may be, nothing would make me more proud.

"I wouldn't be here without so many of you, my amazing family - especially my dad, who taught me never to give up, my friends, my team at @mercedesamgf1 and my fans.

"You've been with me on this journey from the start and it's because of you that I stay focused and determined. I'm forever grateful from the bottom of my heart for every single one of you for your constant support, encouragement and love.

"This season is for Niki Lauda, my incredible friend and mentor who we lost this year, who proved that courage and determination go hand in hand. This one's for you, Niki. I'll continue to make you proud."