The EU's top trade negotiator Cecilia Malmstrom heads to Washington next week in an effort to nail down the parameters of a US trade deal, with both sides at loggerheads over what should be included.

The potential deal would result from a truce reached in July by US President Donald Trump and European Commission chief Jean-Claude Juncker that would scrap customs duties on all goods among other breakthroughs.

The deal was welcomed, especially in Berlin where fear was running high that Trump would deliver on his threat to slap tariffs on auto imports after inflicting similar duties on steel and aluminium.

But the relief was short-lived as major splits fast appeared, with Washington insisting on the inclusion of agriculture in any accord, which the Europeans have refused.

Instead, in the meetings with US Trade Representative Robert Lighthizer on November 13, the EU and US will focus on regulatory cooperation for a limited array of products such as medical drugs and devices as well as cybersecurity.

In the US 'we will see how we can further take forward the work agreed in July in the White House, particularly in the regulatory field," Malmstrom said after meeting trade ministers from EU member states.

'We are in the process of identifying what we can do,' she said.

The pursuit of a scaled back trade deal takes place as a threat of auto tariffs still lurks, with Trump expected to make his decision by February.

The threat is"certainly there', Malmstrom stressed.