Lewis Hamilton has insisted he has no regrets whatsoever about signing for Mercedes for 2013.

Last week Hamilton's current boss Martin Whitmarsh said he didn't understand why the 27-year-old had opted to leave McLaren and he also added that the Englishman does probably, 'on occasion', wonder why he made the decision he did, especially given Mercedes' current predicament and the fact the Brackley-based squad is currently not that competitive.

However, unsurprisingly, Hamilton is adamant that is not the case and on the eve of practice for this Sunday's United States Grand Prix, the 19th and penultimate round in the 2012 F1 World Championship, the Englishman added that he doesn't have 'an ounce of regret'.

"I was a little bit surprised to hear that [what Martin Whitmarsh said], it clearly is absolutely not the case," Hamilton told reporters today in Austin, Texas, according to ESPNF1.com.

"But I've got a great team and I've been with them for such a long time. So I'm sure everyone has emotions within the team, but I'm still here giving 100 per cent to them for the last two races. Of course it's quite emotional for me but I'm very, very happy with the decision that I've made.

"I don't have an ounce of regret, so that's incorrect. But what I do have is a huge amount of love for the team, so leaving is always a tough decision.

"These last few races are going to be tough, but I'm really happy that I've got a new challenge ahead of me.

"I've got to learn, get to grips with and build new relationships with people. Everyone does that in life, I don't know why I can't do that, but I don't have any doubts or regrets about it."