The price of gold has risen to $1,500 an ounce (£1,234.45 at market rates on Wednesday) for the first time in six years as investors seek shelter in low-risk assets amid concerns about the global economy.

The spot gold price rose 1.75% to $1,500.29, its highest level since 2013, taking the metal’s gains this year to 17%.

Gold is considered a safe haven asset and investors traditionally buy into the precious metal at times of economic or political instability.

The value has grown as fears have increased that tension between the US and China could become a full-scale trade war. The US gave assurances that the next round of trade talks would go ahead in September but markets were also alarmed by interest rate cuts in New Zealand, India and Thailand.

Weak German industrial production figures for the second quarter also raised fears about a contraction in Europe’s biggest economy.

Other safe haven assets were also in demand. The yield on 30-year US treasuries fell to as low as 2.145%, not far from a record low of 2.089% set in June 2016.

Yields have been turning negative on government bonds as fears about the global economy have increased. Negative yields mean that investors are prepared to pay to park their money in assets they believe are safe.

Last week, the German 30-year government bond yield went negative for the first time, and some analysts think that the same could happen for US government bonds.

Joachim Fels, an economic adviser to the bond investor Pimco, wrote on his blog: “What was once viewed as a short-term aberration – that creditors are paying debtors for taking their money – has already become commonplace in developed markets outside of the US.

“Whenever the world economy next goes into hibernation, US treasuries, which many investors view as the ultimate safe haven apart from gold, may be no exception to the negative yield phenomenon.”

Donald Trump put pressure on the US Federal Reserve to reduce interest rates, tweeting that the central bank should “cut rates bigger and faster”.

Donald J. Trump (@realDonaldTrump) “Three more Central Banks cut rates.” Our problem is not China - We are stronger than ever, money is pouring into the U.S. while China is losing companies by the thousands to other countries, and their currency is under siege - Our problem is a Federal Reserve that is too.....

Donald J. Trump (@realDonaldTrump) ....proud to admit their mistake of acting too fast and tightening too much (and that I was right!). They must Cut Rates bigger and faster, and stop their ridiculous quantitative tightening NOW. Yield curve is at too wide a margin, and no inflation! Incompetence is a.....

Donald J. Trump (@realDonaldTrump) ....terrible thing to watch, especially when things could be taken care of sooo easily. We will WIN anyway, but it would be much easier if the Fed understood, which they don’t, that we are competing against other countries, all of whom want to do well at our expense!

The yen and the Swiss franc, traditionally seen as low-risk currencies, rose. The yen rose 0.7% to 105.68 against the dollar and the franc gained 0.6% to 0.9702 against the US currency.