The European Central Bank has cut interest rates to 2% in an effort to boost flagging economic growth across the eurozone.

The ECB, making its eighth quarter-point cut in a year, said the 20-member currency bloc needed a reduction in the cost of borrowing as it reeled from the damage caused by Donald Trump’s trade wars.

Economic growth has slowed across the eurozone and especially in France, Germany and Italy, while the outlook for next year is weak, according to forecasts by the EU.

The move cuts the cost of borrowing to less than half the level in the UK, where the Bank of England last month cut interest rates to 4.25%, and the level set in the US by the Federal Reserve of between 4.25% and 4.5%.

The US president has railed against the Fed’s chair, Jerome Powell, and what he describes as its policy of maintaining high interest rates.

Related: UK interest rates more uncertain due to Trump policies, says Bank governor

On Tuesday, Trump noted the repeated interest rate cuts in Europe, and said: “ADP NUMBER OUT!!! ‘Too Late’ Powell must now LOWER THE RATE. He is unbelievable!!!” in a reference to weak private sector payroll numbers given by the US data provider Automatic Data Processing.

The ECB cut its main deposit rate from 2.25% to 2% after inflation across the eurozone fell to 1.9% last month, below the central bank’s 2% target, for the first time since last September.

The ECB said US tariffs would hit growth, but extra government spending on defence would fill some of the gap.

“While the uncertainty surrounding trade policies is expected to weigh on business investment and exports, especially in the short term, rising government investment in defence and infrastructure will increasingly support growth over the medium term,” it said.

However, the ECB’s president, Christine Lagarde, said: “A strong labour market, rising real incomes, robust private sector balance sheets and easier financing conditions … should all help consumers and firms withstand the fallout from a volatile global environment.”

She added: “Are we confident [about the outlook]? I think that would be a bit far-fetched. But we are well-positioned at the moment.”

Lagarde said the vote to cut rates was “virtually unanimous”, after only one member of the governing council voted to keep rates on hold.

The ECB president said it was difficult to know whether interest rates would need to fall further during a period of “significant uncertainty” in the global economy.

She warned that while manufacturing had strengthened, according to recent data, the domestically focused services sector was slowing.