China, the world’s largest producer and exporter of rare earths elements, sharply reduced its overseas shipments of the critical product in the first five months of 2019, amid growing populist calls by nationalists and officials to use the country’s stockpile as a tit-for-tat retaliation in its trade war with the United States.

Exports of rare earth elements fell 16% in May from a month earlier to 3,640 metric tons, according to the General Administration of Customs data.

(Click to enlarge)

Overseas shipments for the first five months of 2019 fell 7.2% to 19,265 metric tons compared to the same period last year. In 2018, China produced 120,000 metric tons or 70% of the world’s total rare earths, according to the United States Geological Survey. In the same period, the US mined 15,000 metric tons of rare earths last year.