President Trump said Tuesday that a 50 percent tariff on copper would be imposed, with officials adding later the new taxes would take effect by August.

“Today, we’re doing copper,” Trump said at a Cabinet meeting. “I believe the tariff on copper, we’re going to make it 50 percent.”

Commerce Secretary Howard Lutnick told CNBC after the meeting that the tariff on copper is set to go into effect by August and aims to increase production in the U.S., teasing that Trump will give more details on social media.

“So copper will be 50 percent and the idea is to bring copper home, bring copper production home. Bring the ability to make copper, which is key to the industrial sector, back home to America. We need that kind of production in America, it’s important,” Lutnick said.

He added, “so that will be out today, you’ll see the president will Truth about it this afternoon. We’ll sign a proclamation as that goes through the ordinary legal process within a day or two days. That will come out, but then copper will be set, likely to be put into place end of July, maybe August 1.”

After Trump announced plans to levy tariffs on the metal, copper futures jumped as much as 17 percent, Bloomberg reported.

Lutnick said in March that Trump plans to introduce steep tariffs on copper imports after he directed Cabinet officials earlier this year to investigate the country’s ability to rely on its domestic supply chain.

Trump has placed other across-the-board tariffs on industry-specific goods, including a 50 percent tariff on steel and aluminum that went into effect last month. The president on Tuesday also threatened to impose 200 percent tariffs on pharmaceuticals.

The tariff on copper comes as the administration sent dozens of letters to trading partners Monday to set tariff rates, ahead of a new deadline for tariffs to go into effect Aug. 1.