EU and US negotiators gathered in Brussels last week for a 14th round of talks on a transatlantic trade and investment partnership (TTIP).
The aim is to finish talks by the end of the year, but given the lingering impasse over access to public procurement and agri-food markets, protections for workers and the environment, and the trade in services, it seems highly unlikely.
The UK's decision to leave the EU has also thrown a spanner in the works.
"Obviously a withdrawal of the UK from the EU market would affect the value of the EU market," said US ambassador Dan Mullaney after the talks.
"Imagine if the United States, for instance, said: 'Well, maybe TTIP will not apply to California'. There is a certain reflection that the parties need to have on those kinds of developments."
The US side is eager to get the negotiations finished before presidential elections in November, and is pushing the EU to put its most powerful bargaining chip on the table: agricultural tariffs, which make up 3pc of the tariffs both sides are seeking to eliminate.
EU negotiators are not budging, indicating talks have not yet reached their end game, said Liam McHale, director of the IFA's Brussels office.
"If you want a deal done by the end of the year, as the US side have said, you need to be negotiating on the 3pc right now, and that's not happening," Mr McHale said. "So you have got to believe there's still a distance to go before that can actually happen."
Negotiators on both sides have tabled proposals in almost all of the up to 30 areas covered by the deal, citing progress on textiles and small businesses.
But there is still masses of technical work needed to bring the two sides together, and new texts have only just been tabled on how to align standards on chemicals, cosmetics, engineering, medical devices, pharmaceuticals and cars.
Agriculture ministers were briefed on the state of play of TTIP at their meeting on Monday, and several EU countries - particularly Germany, France and Austria - are still sceptical about the US deal over fears it will lower European standards.
TTIP also caused a public showdown last week between Irish MEPs, with Sinn Féin's Matt Carthy hitting out at comments by Fine Gael's Brian Hayes that "populists" were the main stumbling block to an agreement.
Mr Carthy claimed the comments were "dripping with arrogance and elitism" and added TTIP would damage food safety and environmental standards, and endanger the rights of workers and consumers.
Energy commissioner Miguel Arias Cañete, was questioned by MEPs last week from parliament's legal affairs committee on his financial interests.
Mr Cañete, a former Spanish environment and agriculture minister, has firmly denied any conflicts of interest, but MEPs brought up a mention of his wife's name in the Panama papers and family ties to two energy companies.
Spanish socialist MEP Iratxe García Pérez alleged the commissioner had "not acted in a morally acceptable or transparent way for someone in his position".
Green MEPs called on him to testify in front of Parliament's special inquiry committee on the Panama Papers.
The committee meeting came the week before Mr Cañete reveals his plans for how sectors such as agriculture and forestry can contribute to reaching the EU's climate change targets.
EU leaders said in October 2014 that they would take into account the "lower mitigation potential" of agriculture and look at how forests could offset the sector's contribution to the climate goals.
And the Paris climate accord this year stated that emission reduction should be done "in a manner that does not threaten food production".
Ireland also wants to see a change to the way the EU measures carbon emission reductions, given the negative effects of the financial crisis on Ireland's GDP and ability to spend on climate change mitigation measures. Irish ministers and officials have met repeatedly with the Commission to press their case.