The police asked protesters to vacate the Ghazipur site by Thursday night.
Traffic jams were reported around Delhi's border with Uttar Pradesh on Thursday night as the police blocked roads and tried to remove protesting farmers from the Ghazipur protest site.
"Ghazipur border closed. Traffic diverted from NH 24, NH 9, Road no 56, 57 A, Kondli, Paper market, Telco T point, EDM Mall, Akshardham and Nizammudin Khatta. Traffic is very heavy in the area and Vikas Marg, Please take an alternate route," news agency ANI quoted Delhi Traffic Police officials as saying.
Hundreds of farmers, protesting the central government's new agricultural reforms, refused to disperse setting up a stand-off with riot police on the outskirts of the capital.
Angry at what they see as laws that benefit large private buyers at the expense of growers, tens of thousands of farmers have been camped peacefully at sites on the outskirts of Delhi for more than two months.
But a procession of tractors on Tuesday turned violent when some protesters deviated from pre-agreed routes, tearing down barricades and clashing with police who responded with tear gas.
Some reached as far as Delhi's historic Red Fort, where they scaled the ramparts and hoisted flags. The violence left one dead and hundreds injured.
Several hundred police arrived at the Ghazipur - one of the three protest sites - to the east of the capital, where hundreds of protesters remain.
The police said the protesters had been ordered to move by Thursday evening. But after meeting with police and government officials, farm leaders had refused.
"We will not empty this protest site," said Rakesh Tikait, one of the farm leaders. "I will take a bullet here if I have to."
Frequent power cuts were witnessed in the evening at the protest site and the water supply to the protesting camps was cut off, reports said.
Protests at other locations around Delhi have not yet been ordered to end.
(With inputs from agencies)