SYDNEY—Even as steel production in the West stumbles because of the coronavirus pandemic, iron-ore prices are surging again as steelmakers in China keep output high to support the economic recovery there.

Iron ore climbed to $136.75 a metric ton on Wednesday, notching up its strongest price in seven years, according to data from S&P; Global Platts. The value of steel’s main ingredient, one of the world’s most-traded commodities, has climbed 16% since the start of November, taking year-to-date gains to 49%.

It has been a difficult year for steelmakers in many parts of the world, as the Covid-19 pandemic buffeted economies, leading mills to scale back manufacturing this spring.

In the U.S., production is gradually increasing, but remains well below year-ago levels with steelmakers cautious about restarting more idled furnaces because of fragile demand and a surge in Covid-19 cases across the country.

U.S. steel output was down 15% year-over-year in October, and had fallen 18% over the first 10 months of this year, according to the World Steel Association.