President Donald Trump’s tariff threats have created such strong demand for UK-held gold, traders are facing potentially weeks-long queues for a chance to withdraw it.

All existing slots at the Bank of England to withdraw gold bars are booked up as market players race to ship the metal to the United States to take advantage of a surge in gold prices there, an official has said. Gold has become more valuable in the US than in other parts of the world as traders worry supply will plunge if Trump’s across-the-board tariffs, both announced and planned, make imports of the metal costlier.

“The US gold market has been trading at a premium to the London market,” Dave Ramsden, deputy governor for markets and banking at the central bank, told reporters Thursday. The owners of the gold bars in its underground vaults have been “looking to take advantage of that price differential,” he added.

As a result, the Bank of England, which has the second-largest stock of gold in the world, has seen strong demand for gold withdrawals, he noted.

“All of those bodies who ship the gold, they’ve all got the … slots they need over the next few weeks. If you were coming in new to us, you might have to wait a bit longer because all the existing slots are booked up,” Ramsden said.

The Bank of England, which is second only to the New York Federal Reserve as a top global custodian of the precious metal, looks after more than 400,000 gold bars worth billions of pounds.

That haul has come under some pressure recently. Meanwhile, gold inventories on the US COMEX exchange — a major market for trading gold, silver and other metals — have almost doubled since the end of October, Commerzbank said in a note Friday.

“The fact that gold is significantly more expensive on the COMEX than (in) other trading centers is likely related to the feared US import tariffs, which could possibly also affect gold,” wrote Carsten Fritsch, a commodity analyst at the German bank. “The deliveries on the COMEX are therefore likely to be primarily driven by concerns about possible supply disruptions.”

The Bank of England’s stock of gold has dipped by about 2% since the end of last year, Ramsden said.

Gold prices have risen in recent weeks thanks to the asset’s safe-haven status, with investors spooked by Trump’s tariff plans. Russia’s drawn-out war in Ukraine and heightened geopolitical tensions in the Middle East are also underpinning demand for the metal, according to UBS.

In addition to being a tangible, scarce asset, gold is different from other traded assets in other ways.

“Gold is a physical asset, so there are real logistical constraints and security constraints,” Ramsden said. “Getting into the (central) bank for me this morning was a bit trickier because there was a lorry in the bullion yard… And the stuff is also quite heavy.”