SINGAPORE (Reuters) -Iron ore futures prices fell on Friday and were set for monthly losses, pressured by U.S. tariff concerns and mounting trade frictions against Chinese steel exports.

    The most-traded May iron ore contract on China's Dalian Commodity Exchange (DCE) closed down 0.74% to 799.5 yuan ($109.72) a metric ton.

The contract has lost 1.17% for the month.

    The benchmark March iron ore on the Singapore Exchange was 1.36% lower at $103.65 a ton, losing 1.94% in February.

U.S. President Donald Trump said on Thursday his proposed 25% tariffs on Mexican and Canadian goods will take effect on March 4 along with an extra 10% duty on Chinese imports.

Trump imposed a 10% tariff on Chinese imports earlier this month, resulting in a cumulative 20% tariff.

Trump also announced plans to impose 25% tariffs on all steel and aluminium imports, which have stirred a new wave of trade frictions against Chinese steel.

Vietnam has announced a temporary anti-dumping levy on some Chinese steel products, while South Korea has provisionally imposed tariffs on Chinese steel imports.

The U.S. steel tariffs are also set to disrupt the Chinese transshipment of steel estimated at $7 billion, undercutting a vital source of sales for China's struggling steel sector, Reuters reported on Thursday.

Meanwhile, shortcomings in China's trade-in scheme, which could reduce expenses on unsubsidised goods and reduce future spending, are raising pressure on authorities to unveil consumer-focused policies with a longer-term impact when China's parliament begins its annual meeting on March 5.

Moreover, China's factory activity likely contracted for a second month in February, keeping alive calls for even more stimulus to prop up depressed domestic demand.

Still, steel benchmarks on the Shanghai Futures Exchange rose. Rebar edged up nearly 0.1%, hot-rolled coil added 0.18%, wire rod was up 0.14% and stainless steel advanced 0.3%.

    Other steelmaking ingredients on the DCE ticked up, with coking coal and coke up 0.41% and 0.78%, respectively.

($1 = 7.2868 Chinese yuan)

(Reporting by Michele Pek; Editing by Eileen Soreng and Mrigank Dhaniwala)