Global oil prices have climbed closer towards US$100 a barrel on Thursday afternoon, with the conflict between Iran and the US showing no sign of de-escalating.Earlier in the day, a tanker was reportedly struck by an unknown projectile off Saudi Arabia's coast.It follows US President Donald Trump threatening to bomb Iranian infrastructure in response to any attacks on ships transiting the Strait of Hormuz.The price of Brent crude has risen around 2 percent this afternoon to a six-week high of around US$96 a barrel.West Texas Intermediate is sitting at around US$88 a barrel.With the announcement of a ceasefire last month, oil prices, which had peaked at US$126 a barrel in April, dropped to around US$72 a barrel.Prices at the pump in New Zealand have not yet reacted to the recent resurgence in global oil prices, with the average price of a litre of 91 sitting at around NZ$2.89 on the Gaspy fuel monitoring site on Thursday afternoon.However, prices at the pump in New Zealand are expected to again climb in coming weeks, with predictions the price for 91 will rise over $3 a litre.