Wall Street stocks climbed higher on Thursday, adding to records as investors greeted optimistic comments from US President Donald Trump about negotiations with Iran while shrugging off a jump in crude prices.

After veering between gains and losses much of the day, all three major US indices finished in the black. That meant fresh records for both the S&P 500 and Nasdaq, which ended up 0.4 percent.

While there is still "nothing concrete" on Iran, commentary from Trump and other figures "is sounding constructive," said Briefing.com analyst Patrick O'Hare.

"By all accounts, the market expects a good outcome here."

Analysts have said that some of the recent strength in stocks reflects a desire to get ahead of an actual deal that could push stocks even higher.

But energy prices have soared since the US-Israel siege on February 28, with Iran blocking most tankers from the Strait of Hormuz. Around a fifth of the world's crude oil and liquefied natural gas normally passes through the waterway.

Trump said the United States and Iran were "very close" to a peace deal, raising hopes that activity in the strait could resume.

"We had to make sure that Iran never gets a nuclear weapon," Trump said. "They've totally agreed to that. They've agreed to almost everything, so maybe if they can get to the table, there's a difference."

But earlier Thursday, US Defence Secretary Pete Hegseth took a tough line on the situation.

"If Iran chooses poorly, then they will have a blockade and bombs dropping on infrastructure, power and energy," Hegseth told a news conference at the Pentagon.

Oil prices bounced on Thursday, with Brent oil futures rising nearly five percent to more than US$99 a barrel.

Stephen Schork of the Schork Group attributed oil market volatility to the uneven rhetoric coming out of both Washington and Tehran.

"We don't know how this ends or how quickly it ends," said Schork.

European stocks ended largely just in the green, with London and Frankfurt adding a little shy of 0.5 percent on the day while Paris slipped slightly.

Global stock markets "have staged one of the fastest recoveries in recent memory," said Matt Britzman, senior equity analyst at Hargreaves Lansdown.

At the same time, "oil prices remain elevated...as investors look towards a possible extension of the ceasefire between the US and Iran while weighing the chances of a broader agreement that could ultimately reopen the Strait of Hormuz," he said.

The S&P 500 rose 0.3 percent, to 7,041, the Nasdaq rose 0.4 percent, to 24,102, while the Dow rose 0.2 percent, to 48,578. (AFP)



Edited by Robert Kemp