ShareSaveAdd as preferred on GoogleOsmond ChiaBusiness reporterAFP via Getty ImagesOil prices rose in Monday morning trade in Asia after President Donald Trump said Iran's response to US proposals to end the war was "totally unacceptable".
Tehran sent its response via Pakistan, which has served as a mediator between the two sides, calling for an immediate end to the conflict and guarantees of no further US-Israeli attacks on Iran, according to Iran's semi-official Tasnim news agency.
International oil benchmark Brent rose by 3.1% to $104.50 (£76.88) a barrel, while US-traded crude increased by 3% to $98.40.
The key Strait of Hormuz waterway has been effectively shut since shortly after the war started on 28 February, severely disrupting global supplies of oil and gas.
Responding to Tehran's terms, Trump posted on social media: "I have just read the response from Iran's so-called 'Representatives.' I don't like it - TOTALLY UNACCEPTABLE."
Washington's terms had included restoration of free transit through the Strait of Hormuz and the suspension on Iranian nuclear enrichment, according to US news outlet Axios.
Israeli Prime Minister Benjamin Netanyahu also said the war with Iran will not be over until its enriched uranium stockpiles are "taken out".
A ceasefire announced in early April to allow time for peace talks has been mostly observed, despite occasional exchanges of fire.
On 21 April, Trump extended the truce indefinitely to give Iran time to present a "unified proposal".
Energy prices have swung wildly since the start of the conflict, while Brent crude has risen back above $100 a barrel since the ceasefire came into effect on 8 April.
The Strait of Hormuz, through which about a fifth of global oil and gas shipments usually passes, has been effectively shut after Tehran threatened to attack vessels that try to cross it in retaliation against US-Israeli strikes.
