BUENOS AIRES — World leaders began arriving in Argentina ahead of a G20 summit dogged by increasingly strident warnings about the impact on the world economy of threatened US trade tariffs.

US President Donald Trump’s trade war with China is a dominant theme at the weekend summit but one sideshow is how leaders deal with the presence of Saudi Crown Prince Mohammed bin Salman.

The de facto Saudi ruler stepped onto Argentine soil bidding to shrug off international outrage over the murder last month of journalist Jamal Khashoggi.

Prince Mohammed appears to be enjoying a pass from Washington. US Secretary of State Mike Pompeo said he had seen no "direct" evidence linking the prince to Khashoggi’s murder at a Saudi consulate in Turkey.

Russian President Vladimir Putin will discuss the killing of Khashoggi when he meets the prince on the summit sidelines, but the "main aim" would be developing Russia-Saudi relations, said Putin’s foreign policy advisory Yuri Ushakov.

Putin would be one of several leaders to meet the Saudi prince, who is also expected to hold talks with Turkish President Recep Tayyip Erdogan and UN chief Antonio Guterres. A meeting with Trump has not been ruled out by the White House.

Human Rights Watch is also waiting for the crown prince, having urged Argentine prosecutors to charge him with war crimes over the Saudi-led military coalition’s action in Yemen.

Trade war shock

Argentina already has plenty to contend with as it hosts its most important international gathering yet in the middle of a biting economic crisis.

Angered by rampant inflation and soaring unemployment, an alliance of Argentine activist groups and trade unions plans a major protest in central Buenos Aires on Friday, the summit’s first day.

Economic troubles could spread much further if Trump goes through on a threat to impose auto tariffs on trading partners including Europe and Japan, the International Monetary Fund warned in a pre-G20 report.

An IMF calculation "suggests that the resulting short-term losses could lower global GDP by about 3/4 per cent."

Trump’s trade war on China is already well underway, and he is threatening to impose deeper tariffs in January unless Chinese leader Xi Jinping yields when they meet on the G20 sidelines.

A White House official said that Trump sees a "good possibility" for a deal to defuse the trade frictions, as Washington demands greater market access and protections for intellectual property by Beijing.

No quick solution

En route to Argentina, Xi said in Spain on Wednesday that his government would indeed boost protection of intellectual property, although foreign companies in China complain they have heard such promises before.

"China will make efforts to further open its door to the outside world," Xi told the Spanish Senate.

"We will make a lot of efforts to speed up market access, improve the investment environment and increase protection of intellectual property."

Wendy Cutler, a former US trade negotiator now at the Asia Society institute in the United States, said the best to expect at the G20 would be a "ceasefire" as both sides agree to go back to talks.

"The issues of concern regarding trade, investment and IPR (intellectual property rights) were not created overnight and cannot be solved quickly," she said.

Ukraine tensions

In Buenos Aires, Trump is also due to sit down with Putin for a bilateral meeting that has taken on added import after Russia fired on and detained three Ukrainian ships in the Sea of Azov near Crimea.

Putin insisted on Wednesday that Russian forces were in the right to seize the Ukrainian ships last weekend, but Trump expressed "deep concern" at Moscow’s actions against a US ally.

Trump on Tuesday threatened to cancel his planned talks with Putin at the G20 summit, but the Kremlin said it still expected the encounter to go ahead.

"The meeting is equally needed by both sides and important for the development of the general situation in the world," Ushakov said. — AFP