Copper prices fell on Tuesday as factory activity in top metals consumer China missed expectations, indicating that U.S. tariffs were affecting the manufacturing superpower while trade tensions between Washington and Beijing drag on.

Benchmark three-month copper on the London Metal Exchange lost 0.5% to $9,571 per metric ton by 0952 GMT.

The most active U.S. Comex copper futures fell 1.9% to $4.768 a pound, reducing the premium against the LME benchmark to $914 a ton from Monday's $1,074.

The Comex futures hit $4.9495, the highest since April 3, on Monday on concerns that U.S. President Donald Trump's plan to double tariffs on steel and aluminium imports to 50% from Wednesday would mean that new U.S. copper tariffs, subject to an ongoing investigation in Washington, were more likely.

"We are seeing a general decline following yesterday's run-up, with traders questioning the sustainability of these levels after another dose of weak China data overnight," said Ole Hansen, head of commodity strategy at Saxo Bank.

China's factory activity shrank for the first time in eight months - the Caixin/S&P Global manufacturing PMI fell to 48.3 in May, the lowest reading in 32 months, a private-sector survey showed.

On Saturday, China's official PMI showed May factory activity fell for a second month.

With the U.S. manufacturing also contracting in May, for a third straight month, traders were waiting for a possible call between Trump and Chinese leader Xi Jinping. According to the White House, they were likely to speak this week.

Providing support to the LME copper were the 21-day moving average, currently at $9,526, and continuing outflows from the stocks in the LME-registered warehouses. LME's daily data showed the inventory fell to 143,850 tons, the lowest in almost a year, after 4,600 were delivered out.

Among other LME metals, aluminium fell 0.8% to $2,446.50 a ton, zinc slipped 0.3% to $2,690, lead dipped 0.5% to $1,971.50, nickel shed 0.8% to $15,415, while tin rose 0.3% to $30,745.

(Reporting by Polina Devitt; Editing by Janane Venkatraman)