Vettel chalked up his fifth win in 11 races at the Belgian Grand Prix on Sunday and moved 46 points clear of Ferrari's Fernando Alonso with eight rounds remaining.
The German is 58 points ahead of 2008 champion Hamilton, who moved up to third overall for Mercedes following Kimi Raikkonen's first retirement in his Lotus, and a fourth successive title is beckoning.
"That's big gap, a huge gap. It's going to be very tough to close that but I'm going to keep pushing," said Hamilton, who finished third at Spa behind Alonso and Vettel after starting on pole position.
Italy is next up, the final round of the European season at the fastest track of all, before Formula One heads east to Singapore, South Korea and Japan and circuits more suited to Hamilton's Mercedes.
"The guys will work over the next few days to try and understand where we were slower (in Belgium). Eau Rouge was particularly slow for us and down the straights," said Hamilton.
"Maybe we will be able to unlock something before the next race but if not then I'm hoping that Singapore onwards will be much better."
Hamilton won the previous race in Hungary, one of the slowest tracks, and has been on pole for four races in a row. He was seen before Spa - a circuit that has ranked among Red Bull's weakest - as the man most likely to take the fight to Vettel.
DOWNFORCE PACKAGE
However, the Briton was powerless to stop Vettel roaring past on the opening lap and Monza promises more of the same.
"When you come to this one and the next one, you get a downforce package and you're kind of stuck with it. It either has or hasn't worked. So we may improve in the next race or be in the same position," said Hamilton.
"It won't be any worse that's for sure. And then onwards we will have the high downforce package that we had in the previous races but hopefully improved again. I'm hoping that we will be more competitive from then on."
Red Bull and Vettel have also typically stepped on the gas in the second half of the season once Spa and Monza - races that team principal Christian Horner called their 'Achilles Heel' - are behind them.
"It's going to be very, very tough, undoubtedly," said Hamilton. "He (Vettel) has just had a phenomenal car for a long, long time and it still is phenomenally quick and he does the job. So it's a perfect package.
"But we've had some really strong races and we've been there or thereabouts in competing with them and we have finished ahead of them in the past so it doesn't mean we can't do that in these next races."
Alonso had a commanding lead over Vettel going into the Belgian Grand Prix last year but ended up losing out by three points at the end of the season.
Horner said there were no guarantees that situation could not be reversed.
"Fernando managed to (lose it) last year so nothing is impossible. 25 points for a victory, a couple of DNFs (retirements) and somebody puts a run together and you can be on the back foot again," he told reporters.
"I don't think you can write anybody off... There are still a lot of points available. But you'd probably have to say the podium (drivers) today are probably going to be the main contenders between now and the end of the year."
(Reporting by Alan Baldwin; Editing by John O'Brien)
