Extinction Rebellion has offered to “pause” the protests that have caused widespread disruption across central London for seven days.
The group said it would mark “a new phase of rebellion” to achieve “political aims”.
A total of 831 people have been arrested during the climate change protests and 42 people charged.
Hundreds of officers from other forces have been sent to the capital to help the Metropolitan Police.
Extinction Rebellion said it hoped to negotiate with the Mayor of London and the Met over continuing its demonstrations at Old Palace Yard in Westminster and leaving other sites.
Farhana Yamin, from the group, said being able to “pause” the protests showed it was an “organised and a long-term political force to be reckoned with”.
“Today marks a transition from week one, which focused on actions that were vision-holding but also caused mass disruption across many dimensions,” she said.
“Week two marks a new phase of rebellion focused on negotiations where the focus will shift to our actual political demands.”
Police have been trying to confine the protests to Marble Arch but demonstrators have ignored the threat of arrest and continued to block roads across the capital.
Oxford Circus has reopened to traffic after officers cleared protesters but they continue to occupy Parliament Square.
Campaigners who glued themselves to the roof of a lorry on Waterloo Bridge were removed and the lorry was cleared in the early hours.
At about 15:40 BST on Sunday, activists on Waterloo Bridge began removing their collection of trees and plants.
Police have also removed the skate ramp, cooking tents and other infrastructure from the activists’ camp on the bridge.
Met Commissioner Cressida Dick said she had never experienced anything like it in her career.
She said: “I’ve been a police officer for 36 years – I have never known an operation, a single operation, in which over 700 people have been arrested.”
Ms Dick added she was grateful for the help from hundreds of police officers drafted in from several forces, including the neighbouring City of London Police.
Officers from Kent, Sussex, Essex, Hampshire and Greater Manchester have also been sent.
Teenage activist Greta Thunberg is expected to address Extinction Rebellion members at Marble Arch later ahead of meeting senior British politicians next week.
Mayor of London Sadiq Khan said the protests were “counter-productive” to London and “more than 9,000 officers” had been responding to the demonstrations.
He said: “Londoners have suffered too much disruption and the policing operation has been extremely challenging for our over-stretched and under-resourced police.
“I’m extremely concerned about the impact the protests are having on our ability to tackle issues like violent crime if they continue any longer.
“It simply isn’t right to put Londoners’ safety at risk like this.”
What is Extinction Rebellion?
Since the group was set up last year, members have shut bridges, poured buckets of fake blood outside Downing Street, blockaded the BBC and stripped semi-naked in Parliament.
It has three core demands: for the government to “tell the truth about climate change”; to reduce carbon emissions to zero by 2025; and to create a citizens’ assembly to oversee progress.
Controversially, the group is trying to get as many people arrested as possible.
But critics say they cause unnecessary disruption and waste police time when forces are already overstretched.