Zinc neared a one-month high while other metals came under pressure in London, with top producer Glencore warning that Europe’s energy crisis poses a substantial threat to supply.

Glencore has already suspended production at one of its zinc smelters in Europe, leading to a sharp drop in its metal output this year, and on Thursday it disclosed that its other smelters in the region are barely turning a profit. While risks to industrial-metals demand are mounting, Europe’s power crisis is also weighing heavily on the supply outlook, Glencore said.

“On the supply side, the current energy supply and price environment poses a significant threat, as Europe accounts for around 30% of ex-China metal production,” Glencore said in its half-year earnings report. “Most fundamental indicators continue to point to tight market conditions, particularly in the West.”

Like other miners, Glencore is facing a broad increase in production costs, with its operations being buffeted by inflation in energy, labor, freight and consumables, as well as a decline in byproduct prices. Its copper business has been hit particularly hard by the recent slump in cobalt prices, leading to a sharp jump in its cost estimates for the year.

Copper traded little changed on the London Metal Exchange on Thursday, with investors weighing threats to growth after Federal Reserve officials signaled again that they will do what’s required to cool high inflation even if that raises the risk of recession. Copper has plunged about 30% from a March record as base metals have been battered by mounting concerns over a global recession.

US-China tensions are also clouding the outlook following House Speaker Nancy Pelosi’s visit to Taiwan. China’s military kicked off three days of live-fire military exercises around Taiwan in response to Pelosi’s visit, even as Taipei played down the impact on flights and shipping.

Zinc rallied as much as 2.1% to $3 344.50 a ton on the LME and was trading at $3 335 a ton as of 12:01 p.m. local time. Aluminum was little changed, while lead and tin declined.