Farmers have staged massive protests in France over the past few weeks, angry about rising costs and cheap imports, following similar action in other European countries, including Germany and Poland. French farmers have in particular objected to ongoing talks on a trade deal between the EU and Mercosur nations, which they say would allow cheap food imports that do not meet strict EU standards.

"(Macron) has very firmly reiterated to the Commission the fact it was impossible to conclude talks in these conditions," a French presidential adviser told reporters ahead of Thursday's EU summit.

The adviser added that the EU understood it was impossible to reach a deal in this context and that EU talks with Mercosur countries had been stopped.

"It is our understanding it has instructed its negotiators to put an end to the negotiation session underway in Brazil and in particular cancel the visit of the Commission's vice-president that had been envisaged in view of a conclusion," he added.

The Commission said that EU and Mercosur technical experts remained in contact, including meetings on Jan. 25-26 in Brazil, but some important questions remained open.

"The EU focus remains on ensuring that the agreement delivers on the EU's sustainability goals, while respecting the EU's sensitivities in the agricultural sector," a spokesperson said.

France has repeatedly expressed reservations about the EU-Mercosur deal, the text of which was agreed in 2019 after 20 years of on-off negotiations. Several other EU members back the deal. Talks resumed after the EU sought assurances on climate change and deforestation from Mercosur countries, a customs union formed by Brazil, Argentina, Uruguay and Paraguay.

Brazil's foreign ministry declined to comment on Macron's statements, but a ministry source said that the talks "are not carried out with individual countries or presidents, but between Mercosur and the European Commission."

EU and Mercosur trade negotiators met in Brasilia for two days last week but reported "limited progress" according to one diplomat involved in the talks, who was sceptical that the deal could be concluded before the World Trade Organization (WTO) ministerial meetings next month as some hoped.

"Negotiations are proceeding slowly but in the right direction. But it will take more time," another diplomat told Reuters.

(Reporting by Michel Rose in Paris, Lisandra Paraguassu in Brasilia and Philip Blenkinsop in Brussels; Editing by Benoit Van Overstraeten and Tomasz Janowski)