London, June 19 (AFP/APP):Global stock markets tumbled Tuesday on rising fears of a trade war after US President Donald Trump threatened fresh tariffs on Chinese imports and Beijing warned of countermeasures.

Eyes were also on talks in Germany between the country's Chancellor Angela Merkel and French President Emmanuel Macron on EU reform.

Merkel and Macron have both stressed that the bloc must learn to stand its ground on the world stage, as Trump openly challenges the EU with a trade war and over security and climate policy.

“The clear escalation that's occurred in recent days has shaken investors and appears to have brought an end to the good run that US stock markets had been on since the start of May,” wrote Craig Erlam, senior market analyst at Oanda.

“While Chinese stocks are faring much worse at the moment, US companies are obviously not immune to a trade war and could come under more pressure unless both sides find a solution.”

Trump has asked the US Trade Representative to identify $200 billion worth of imports to be targeted, adding he would hit a further $200 billion if Beijing retaliates.

The US and China, the world's top two economies, already announced Friday tit-for-tat measures on goods valued at about $50 billion as the US president pushes ahead with his protectionist America First agenda.

– 'Beyond tit-for-tat' –

Stephen Innes, head of Asia-Pacific trading at Oanda, said Trump's latest move goes “beyond 'tit-for-tat' levels and, predictably, investors are running for cover under the haven umbrellas as global equity indices are crumbling under the weight of an escalating trade war”.

The trade tensions, coupled with a strong dollar, have particularly hurt emerging markets, FXTM research analyst Lukman Otunuga wrote.

“Intensifying trade tensions may trigger fears of increasing global protectionism negatively impacting growth in developing nations — ultimately spelling more trouble for (emerging market) currencies and stocks,” he wrote.

Market volatility has seen Argentine stocks take a spectacular dive in the past 24 hours.

The country is seeking support from the International Monetary Fund in return for a commitment to reforms of an economy weakened by a chronic budget deficit and more than 20 percent annual inflation.

Meanwhile, oil prices slid ahead of a key OPEC meeting on crude output levels on Friday, in an apparent sign that investors were expecting the cartel and Russia to hike output.

And while recent statements by officials from oil giants Saudi Arabia and Russia appear to indicate that a hike may well be on the horizon, OPEC summits can be full of surprises.

Asian trading floors were a sea of red Tuesday, with Hong Kong closing down 2.8 percent.

Hong Kong-listed shares in Chinese telecoms equipment maker ZTE dived 24.8 percent after US senators voted to reimpose a seven-year ban on US high-tech chip sales to the company.

The move defied the White House's decision to replace the ban with a $1.4 billion fine, providing a lifeline to the firm threatened with collapse as it relies on the crucial US hardware.

Trump's intervention to help the firm was seen at the time as part of a move to smooth over tensions with Beijing as they embarked on talks to avert a trade war, with the president tweeting on May 13 that too many Chinese jobs were at threat.

ZTE stock has now lost around 60 percent since trading in it resumed last week after a two-month suspension that came in following the initial ban.

– Key figures around 1330 GMT –

New York – Dow Jones: DOWN 0.4 percent at 24,987.47 points
London – FTSE 100: DOWN 0.5 percent at 7,597.17
Frankfurt – DAX 30: DOWN 1.3 percent at 12,667.91
Paris – CAC 40: DOWN 1.1 percent at 5,388.50
EURO STOXX 50: DOWN 0.6 percent at 3,043.65
Tokyo – Nikkei 225: DOWN 1.8 percent at 22,278.48 (close)
Hong Kong – Hang Seng: DOWN 2.8 percent at 29,468.15 (close)
Shanghai – Composite: DOWN 3.8 percent at 2,907.82 (close)
Euro/dollar: DOWN at $1.1558 from $1.1615 at 2100 GMT
Pound/dollar: DOWN at $1.3175 from $1.3243
Dollar/yen: DOWN at 109.85 yen from 110.56 yen
Oil – Brent Crude: DOWN 50 cents at $74.80 per barrel
Oil – West Texas Intermediate: DOWN $1.05 at $64.80