The dollar continued to face pressure amid uncertainty over tariffs, while equity markets were largely lower.

"Traders focused on the prospect of a US-Iran nuclear deal which could see economic sanctions lifted on the latter and potentially lead to greater supplies of oil," noted Russ Mould, investment director at AJ Bell.

Trump's remarks came after Iran held its fourth round of talks with the US administration, which has said it wishes to avoid a threatened military strike by Israel on Tehran's contested nuclear programme.

Both main crude contracts plunged more than three percent in value on hopes that US sanctions on Iran might be lifted as part of the deal.

That could, in turn, increase the Islamic republic's oil exports.

In European equities trading, London's stock market edged up as official data showed Britain's economy grew more than expected in the first quarter -- before UK business tax hikes and US tariffs took effect.

Wall Street's three main indices opened lower following a warning by Walmart of price hikes due to US tariffs that dampened sentiment, with the Dow shedding 0.4 percent.

Shares in Walmart slumped 4.7 percent after the company reported first quarter revenue growth of 2.5 percent that narrowly missed analyst expectations.

Profits came in at $4.5 billion, down 12.1 percent from the year-ago level but topping analyst expectations.

However Walmart's CEO warned of higher prices due to tariffs, welcoming a de-escalation of US President Donald Trump's trade war with China but saying the levies remain too high for the retailer to absorb.

"We will do our best to keep our prices as low as possible but given the magnitude of the tariffs, even at the reduced levels, we aren't able to absorb all the pressure," Chief Executive Doug McMillon told investors.

Meanwhile, investors awaited fresh developments in trade talks, with countries looking to reach deals to avoid Trump's tariff blitz.

With excitement from the China-US detente fading, markets are seeking new catalysts.

Stock markets have surged past the levels seen before Trump's April 2 "Liberation Day" bombshell that hit countries worldwide with US tariffs.

After figures on Tuesday showing US inflation came in a little below forecasts in April, wholesale price data released on Thursday showed they unexpectedly fell 0.5 in April due largely to a sharp drop in services costs.

Briefing.com analyst Patrick O'Hare said the data showed a sharp drop in wholesale machinery and vehicle sales.

"That suggests wholesalers were likely absorbing some tariff impacts, which is good for the end customer but not necessarily for earnings," he said.

April retail sales, data, also released Thursday, came in nearly flat.

The 0.1-percent gain was significantly down from March's revised growth of 1.7 percent, as buyers earlier sought to get ahead of Trump's sweeping new tariffs, many of which took effect in April.

However, analysts have pointed out that the real impact of tariffs would not be seen until May's figures are released and warned that there were still plenty of bumps in the road ahead.

- Key figures at around 1330 GMT -

West Texas Intermediate: DOWN 2.5 percent at $61.55 per barrel

Brent North Sea Crude: DOWN 2.5 percent at $64.46 per barrel

New York - Dow: DOWN 0.4 percent at 41,895.51 points

New York - S&P 500: DOWN 0.4 percent at 5,871.89

New York - Nasdaq Composite: DOWN 0.6 percent at 19,023.65

London - FTSE 100: UP 0.2 percent at 8,604.82

Paris - CAC 40: DOWN 0.2 percent at 7,824.78

Frankfurt - DAX: UP 0.2 percent at 23,561.19

Tokyo - Nikkei 225: DOWN 1.0 percent at 37,755.51 (close)

Hong Kong - Hang Seng Index: DOWN 0.8 percent at 23,453.16 (close)

Shanghai - Composite: DOWN 0.7 percent at 3,380.82 (close)

Euro/dollar: UP at $1.1202 from $1.1178 on Wednesday

Pound/dollar: UP at $1.3304 from $1.3268

Dollar/yen: DOWN at 145.83 yen from 146.65 yen

Euro/pound: UNCHANGED at 84.21 pence

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