Lewis Hamilton admits it will be "very tough" to beat Sebastian Vettel to the world drivers' title but insists he is "going to keep pushing".
The Mercedes driver
is 58 points behind Vettel with a maximum of 200
available after the Red Bull driver's dominant victory in Sunday's Belgian Grand Prix.
Watch Hamilton's Belgian GP pole lap
"It's a big, big gap. It's a huge gap," said Hamilton,
who finished third at Spa behind Ferrari's Fernando Alonso.
Hamilton admitted it was "difficult" to see Vettel in such a strong position.
The Englishman started from pole position
but was passed by the German on the first lap,
before being demoted by Alonso 14 laps later on.
Hamilton's Mercedes did not have the pace to keep up with his two rivals.
"There's nothing you can do," Hamilton said. "It's difficult when people pull away from you and there is nothing you can do about it.
"I feel happy we've extended our lead [in the constructors' championship] ahead of Ferrari, and also I'm up to third [in the drivers' ahead of Lotus's Kimi Raikkonen], so I have come and done what I planned to do.
"But it is difficult when he is pulling away at the rate sometimes he pulls away."
Vettel is 46 points ahead of Alonso, who is second in the championship, and is well on course for his fourth consecutive world title, a feat only Juan Manuel Fangio and Michael Schumacher have previously managed.
Hamilton, who won the previous race in Hungary,
said: "He has just had a phenomenal car for a long, long time and it's still phenomenal and he does the job, so it's a perfect package.
"But we have had some really strong races and we've been competing with him and we have finished ahead of him in the past so it doesn't mean we can't do that in these next races. But it is getting closer and closer to the point where we need to be finishing ahead every time to close that gap."
Hamilton said he believed his Mercedes team's form in Spa meant Vettel and Alonso would start favourites at the next race, the Italian Grand Prix on the high-speed Monza track on 8 September.
Hamilton seals first Mercedes win
But he is optimistic he will be fully competitive
for the final seven races, starting in Singapore on 22 September.
"They're more windy circuits, more higher-downforce circuits," he said.
"These two circuits [Spa and Monza], you get a downforce package and you're kind of stuck with it. It either has or hasn't worked.
"You may improve in the next race or be in the same position. We won't be any worse.
"Then afterwards we'll have the high-downforce package we had in the previous races but hopefully it should be improved again. So I'm hoping we'll be more competitive from then on."