The Uber chief executive, Dara Khosrowshahi, has apologised for the "mistakes we've made" after the taxi-hailing firm lost its London licence.
He said in an open letter that Uber would appeal against the city's decision, but accepts it "must change".
Earlier, London Mayor Sadiq Khan said Uber had put "unfair pressure" on Transport for London (TfL), with an "army" of PR experts and lawyers.
On Friday, TfL denied Uber a new licence to operate in London.
TfL cited concerns over public safety and security.
However, Uber says it has followed the regulator's rules and works closely with the Metropolitan Police.
Mr Khosrowshahi, who took over at Uber less than a month ago, wrote: "While Uber has revolutionised the way people move in cities around the world, it's equally true that we've got things wrong along the way.
"On behalf of everyone at Uber globally, I apologise for the mistakes we've made."
In a letter addressed to Londoners, the new boss said the firm "won't be perfect, but we will listen to you".
Mr Khan, who is also chairman of TfL, said on Monday: "What you can't do is have a situation where unfair pressure is brought on a quasi-judicial body, where there are officials working incredibly hard.
"I appreciate Uber has an army of PR experts, I appreciate Uber has an army of lawyers - they've also made aggressive threats about taking us to court."
While Mr Khan chairs the TfL board, according to the organisation, he was not involved in the process of deciding whether to issue Uber with a licence.
That is handled by TfL's taxi and private hire department.
Uber is keen to hold talks with officials from that department "as soon as possible", Fred Jones, a senior executive with Uber in the UK, told the Today Programme.
Mr Jones said that Uber was "not clear" about the issues raised by TfL when it denied the company a licence.
One of the points raised by TfL was Uber's "approach to how Enhanced Disclosure and Barring Service (DBS) checks are obtained" for its drivers.
That part of the process was not even handled by Uber, said Mr Jones. Instead, the drivers organised their own DBS check and took that paperwork to TfL.
TfL then reviews that application before giving the driver a licence allowing them to drive for Uber.
TfL would not elaborate further on its issue with the way in which Uber organises DBS checks, because that would be likely to come up when Uber appealed against the decision.
It would only repeat that it was Uber's "approach" to DBS checks that was the problem.
More than 730,000 people have signed an online petition in a bid to keep Uber operating in London after its licence expires on 30 September.