Donald Trump has begun trade talks with top European Union officials at the White House, suggesting that the US would be “pleased” if all tariffs, barriers and subsidies could be scrapped.

The US president sat in the Oval Office alongside Jean-Claude Juncker, the European Commission president who is hoping to persuade him not to impose punishing tariffs on car imports and risk an all-out trade war.

Trump and Juncker appeared cordial as they sat together. Trump told reporters: “We want to have a fair trade deal and we’re looking to have a fair trade deal and hopefully we can work something out.

“Over the years the United States has been losing hundreds of billions of dollars with the European Union, and we just want it to be a level playing field for our farmers, for our manufacturers, for everybody, and we also want a big beneficiary frankly to be the European Union, so we think it can be good for everybody and that’s what we’re here to discuss.”

Juncker responded: “We are close partners, allies, not enemies. We have to work together. We are representing half the world’s trade … We should talk of reducing tariffs, not of increasing tariffs. That’s what we have to do.”

With a bust of Winston Churchill looking over his shoulder, Trump said he agreed. “If we could have no tariffs and no barriers and no subsidies, the United States would be extremely pleased … We want reciprocal. So whether it’s with European Union or others, it has to be reciprocal in nature at a minimum. We’re working on that and I think we’re making tremendous strides.”

He ignored shouted questions from the media ahead of the talks with Juncker.

Hours before the meeting on Wednesday, a last-ditch effort to avert a full-blown transatlantic trade war, Trump attacked the EU and suggested it was Brussels that stood in the way of free trade.

Trump has repeatedly threatened to impose further tariffs on European car imports over a perceived imbalance in trade between the two economic blocs.

The US president tweeted: “Tariffs are the greatest! Either a country which has treated the United States unfairly on Trade negotiates a fair deal, or it gets hit with Tariffs. It’s as simple as that – and everybody’s talking! Remember, we are the ‘piggy bank’ that’s being robbed. All will be Great!”

He later added: “The European Union is coming to Washington tomorrow to negotiate a deal on Trade. I have an idea for them. Both the US and the EU drop all Tariffs, Barriers and Subsidies! That would finally be called Free Market and Fair Trade! Hope they do it, we are ready – but they won’t!”

Cecilia Malmström, the EU trade commissioner, who travelled to Washington with Juncker, said the EU was lining up a second round of US goods to be hit with tariffs should the White House meeting end in failure.

The EU is looking at 20% tariffs on €10bn (£8.9bn/$11.7bn) of US products, or a lower tariff on a longer list of €20bn of US goods. Brussels has already applied tit-for-tat levies on €2.8bn of US products, including Harley-Davidson motorbikes and bourbon.

Malmström told the Swedish newspaper Dagens Nyheter: “We hope that it doesn’t come to that and that we can find a solution. If not, the EU commission is preparing a rather long list of many American goods. It would be around $20bn.”

At a meeting of the leaders of the G7 in Canada last month, Trump accused Juncker of being a “brutal killer”, presumably with regard to the EU’s trade policies.

Trump has repeatedly complained about the EU’s 10% tariff on imported vehicles. The US has a 2.5% levy on imports of passenger vehicles. The EU has responded that Brussels is more generous than Washington in other areas.

Trump is nevertheless reportedly ready to apply a 20% tariff on imports of cars and auto partsunless the EU rethinks its trade policies. Juncker is seeking to avert such a unilateral move by making an offer, but only if the US lifts punitive tariffs on European steel and aluminium appliedthis year.

In the unlikely event that Trump agrees, Juncker will suggest that significant makers of cars and car parts, including Japan and South Korea, negotiate a multilateral agreement with the aim of reducing tariffs on those products to zero.

A second proposal would be for a TTIP-lite deal, reducing the Transatlantic Trade and Investment Partnership, a comprehensive trade agreement between the US and the EU pursued by Barack Obama and dumped by Trump, to a limited deal focused only on industrial tariffs.

There are signs that Trump’s trade policies are causing the US economy some difficulty, and creating political problems in Washington.

On Tuesday, the US administration was forced to promise a $12bn aid plan to subsidise farmers hit by retaliatory tariffs imposed by China and the EU.

The Republican senator Ron Johnson voiced the views of free traders in Trump’s party, saying: “This is becoming more and more like a Soviet-type of economy here. Commissars deciding who’s going to be granted waivers, commissars in the administration figuring out how they’re going to sprinkle around benefits. I’m very exasperated. This is serious.”

Juncker, who has been more emollient in his language about Trump than Donald Tusk, the European council president, will give a speech titled Transatlantic Relations: At a Crossroads after his White House meeting. Tusk has accused Trump of forging a new US approach to foreign relations in which there are no friends, only foes.