Copper prices in London edged up on Thursday, with markets tracking inflows of the industrial metal to the U.S. as demand rose ahead of potential tariffs, and a downward move in the dollar index further lent support.

The benchmark three-month copper on the London Metals Exchange (LME) added 0.1% to $9,941 a metric ton as of 0707 GMT. In the last session, prices hit $10,164.5 a ton, the highest since June 7.

Traders have been bidding up copper prices after U.S. President Donald Trump ordered a probe into potential tariffs on copper imports to rebuild U.S. production of the metal.

"Trump's announcement has led to frontloading and (the) market is trying to price in tariffs; there have been (a) lot of inflows in the U.S. market," said ANZ Commodity Strategist Soni Kumari.

"Once there is clarity around tariffs, this will subside as demand from (the) U.S. will soften and that will weigh on prices."

Citi Research forecast that a 25% U.S. copper import tariff would be imposed in the second quarter of this year and lowered its three-month price outlook to $9,500 per ton, down from $10,000, the brokerage said in a note.

On Wednesday, Trump unveiled a 25% tariff on imported cars and light trucks starting next week, widening the global trade war.

The dollar index, which measures the U.S. currency against six rivals, drifted lower.

A softer dollar makes greenback-priced commodities cheaper for buyers using other currencies.

Among other metals, LME aluminium added 0.3% to $2,613.5 a ton, lead fell 0.6% to $2,078.5, zinc dipped 0.4% to $2,945, tin advanced 0.4% to $35,195 and nickel eased 0.3% to $16,190 a ton.

SHFE copper slid 1.03% to 81,560 yuan ($11,229.21) a ton, SHFE aluminium gained 0.6% to 20,815 yuan a ton, zinc dropped 0.3% to 24,105 yuan, lead advanced 0.2% to 17,615 yuan, nickel was down 0.05% to 130,030 yuan and tin rose 0.8% to 281,010 yuan. ($1 = 7.2632 Chinese yuan)

(Reporting by Neha Arora; Editing by Sumana Nandy, Janane Venkatraman and Rashmi Aich)