Brent crude oil topped $70 a barrel Thursday for the first time since September as United States President Donald Trump ramped up geopolitical tensions by threatening military strikes on Iran.

In London morning deals the Brent North Sea crude contract, an international benchmark, jumped 2.4 per cent to $70.06 a barrel.

The US benchmark West Texas Intermediate climbed 2.6 per cent to $64.82 per barrel.

In a post on his Truth Social network Wednesday, Trump said Iran needed to negotiate a deal over its nuclear programme, which the West believes is aimed at making an atomic bomb.

“Hopefully Iran will quickly ‘Come to the Table’ and negotiate a fair and equitable deal — NO NUCLEAR WEAPONS — one that is good for all parties. Time is running out, it is truly of the essence!” Trump said.

“The next attack will be far worse! Don’t make that happen again,” he added, referring to American strikes against Iranian nuclear targets in June.

Iran’s Foreign Minister Abbas Araghchi warned that Tehran would respond immediately and forcefully to any US military operation.

Derren Nathan, head of equity research at Hargreaves Lansdown, said a conflict risked impacting Iran’s daily oil production of three million barrels as well as disrupting tankers carrying oil and gas through the Strait of Hormuz, a key transit hub for energy supplies.

“Brent crude oil is now at the highest level seen in four months as the war of words… ratchets up,” he said.