The US and the European Union have agreed a truce in their near 17-year conflict over aircraft subsidies, bringing to a close one set of Trump-era tariffs which had soured relations between them.

The two sides have been battling since 2004 in parallel cases at the World Trade Organization over subsidies for US planemaker Boeing and European rival Airbus.

They agreed in March to a four-month suspension of tariffs on $11.5 billion of goods from EU wine to US tobacco and spirits, which they had imposed in response to the row.

Today they said they would remove them for five years, while still working on an overall deal on what subsidies to allow.

European Commission president Ursula von der Leyen said in a statement that the EU-US summit with US President Joe Biden had begun with a breakthrough.

US Trade Representative Katherine Tai spelled out Washington's thoughts on the deal, seen as allowing them to focus on the threat posed by China's nascent commercial aircraft industry.

Tai said the two sides had agreed to clear statements on what support could be given to large civil aircraft producers and would cooperate to counter investments in aircraft by "non-market actors", referring specifically to China.

"We have committed to meaningful cooperation," she said.

Former EU member Britain, which was also involved in the dispute as a home to Airbus production, said it hoped for a similar deal within days. Tai is due to meet her British counterpart Liz Truss tomorrow.

The EU-US agreement removes one of two major trade irritants left over from Donald Trump's presidency, the other being tariffs imposed on grounds of national security on EU steel and aluminium imports.

The European Commission, which oversees EU trade policy, last month suspended for up to six months a threatened June 1 doubling of retaliatory tariffs on Harley-Davidson motorbikes, US whiskey and motorboats.

It also refrained from slapping tariffs on more US products from lipstick to sports shoes.

Brussels and Washington have said they would seek to address excess global steel capacity largely centred in China.

The US may find it tougher to remove the metals tariffs, which also apply to other countries such as China, because they are still backed by many US metal producers and workers.

Brussels is also pushing what is dubs a new "positive agenda" on trade with Washington, including forging an alliance to drive WTO reform.

The two are also likely to agree to cooperate on trade and technology, such as for setting compatible standards and facilitating trade in artificial intelligence.

The head of the World Trade Organization said today she was delighted that Washington and Brussels had resolved a dispute over aircraft subsidies, saying it showed that "even the most seemingly intractable differences can be resolved".

"This agreement proves that with hard work and political will WTO Members can achieve historic results," said WTO Director-General Ngozi Okonjo-Iweala, who took office in March and is aiming to overhaul the Geneva-based trade watchdog.

The 17-year conflict was one of the WTO's longest running disputes.