The European Union has prepared a list of tariffs worth 21 billion euros ($24.52 billion) on US goods if the two fail to reach a trade deal, Italy's Foreign Minister Antonio Tajani said in a newspaper interview on Monday.

US President Donald Trump on Saturday threatened to impose a 30 percent tariff on imports from Mexico and the EU starting on August 1, after weeks of negotiations with major US trading partners failed to reach a comprehensive deal.

Tajani also told the daily Il Messaggero that, to help the eurozone economy, the European Central Bank should consider a new 'quantitative easing' bond-buying programme and further interest rate cuts."

The European Union said on Sunday it would extend its suspension of countermeasures to US tariffs until early August and continue to press for a negotiated settlement.

Tajani said the 21-billion-euro package of tariffs the EU has already prepared could be followed by a second set if a deal with the US proves impossible. He added, however, that he was confident that progress could be made in negotiations.

"Tariffs hurt every one, starting with the United States," he said. "If stock markets fall that puts at risk the pensions and the savings of the Americans."

He said the goal should be "zero tariffs" and an open market among Canada, the United States, Mexico and Europe.

German Chancellor Friedrich Merz said on Sunday he would work intensively with French President Emmanuel Macron and European Commission President Ursula von der Leyen to resolve the escalating trade war with the United States.