India attempted to calm nearly a week of raucous protests by meeting with farmers on Tuesday after rallies against agricultural reforms sparked violent clashes with police on the outskirts of the capital.

The plight of farmers is a major political issue in India with thousands committing suicide in recent years due to debt and increasingly erratic weather patterns blamed on climate change.

Laws rushed through parliament earlier this year by Prime Minister Narendra Modi's government mean growers are now free to legally sell their produce anywhere in India instead of getting guaranteed prices from state-run markets.

Farmers were met with tear gas and water cannon when they marched on New Delhi last week and are now facing-off against heavily-armed security forces at two major entry points to the city.

Many of the demonstrators come from northern Punjab state which is controlled by the Congress party, the main opposition to Modi's administration.

Congress leaders have argued the farming reforms will give private corporations free rein to exploit farmers, an argument echoed by the protesters.

"As big players... enter the field, our existing government agriculture markets will become redundant and private players will exploit the farmers," said Harmandeep Singh, who joined the demonstration from Punjab.

Singh said the farmers are calling for a written guarantee from the government that the existing minimum price for crops would not be removed.

Addressing a rally on Monday, Modi accused the opposition of spreading "misinformation" about the reform package.

But his government brought forward talks with farmer group representatives by two days on Tuesday in an effort to forestall more rallies after protesters announced plans to blockade other routes into the city.

Elsewhere police set up roadblocks and arrested demonstrators trying to march into the capital.

Trudeau 'concerned'

The protests have also provoked a diplomatic spat between India and Canada, which is home to a large Punjabi-origin diaspora.

Canadian Prime Minister Justin Trudeau published a video message on Twitter in which he said the demonstrations were "concerning" and defended the right to peaceful protest.

"We've reached out through multiple means directly to the Indian authorities to highlight our concerns," he added.

India's foreign ministry responded by hitting out at "ill-informed comments by Canadian leaders relating to farmers in India", without directly naming Trudeau.