A new round of negotiations with the bloc ended last week, but EU officials no progress had been made and that they needed to address issues like the future relationship between Britain and the EU.
Negotiations appeared to stall after the EU’s chief negotiator, Michel Barnier, accused the British government of seeking to retain the benefits of EU membership while leaving the bloc.
“We are ready to intensify negotiations. Nothing has been formally agreed, but that is something that we can discuss,” May’s spokeswoman told reporters on Monday. “Typically in negotiations as time goes on you see the pace pick up.”
The EU is expected to announce a decision next month on whether to move talks to a future trade deal with the UK.
Britain is signaling that it is ready to abandon the current format of one round of talks each month. UK officials are reportedly calling for week-by-week negotiations until a breakthrough is reached.
EU officials have been complaining that the British side has been weaseling out of its obligations and failing to address the three key points raised in previous Brexit talks: EU citizen rights, Northern Ireland's border and a divorce bill.
On Sunday, Brexit Secretary David Davis dismissed reports that the UK had secretly agreed to pay an "exit" figure of up to £50 billion.
The prime minister’s spokeswoman said the government would not come up with a price tag until wider talks began.
"We are not there yet," she said, while suggesting the divorce bill was "inextricably linked" to the UK's future relationship with the EU.
Barnier warned last week that the UK faced "extremely serious consequences" if it left the EU’s single market.
May's spokeswoman said “the British people have heard those arguments.”