The oil price has gone above $40 a barrel for the first time this year as commodities continue to rally.
Brent crude, used as an international benchmark, rose more than 5% to trade at $40.83 a barrel.
Oil dropped below $28 in January, but has since risen as part of a wider recovery in energy and metal prices.
The price of iron also shot up, rising 20% amid greater optimism about Chinese economic growth and demand for the metal in the country's refineries.
The price of Brent crude has now gone up more than 40% from the low it reached in January, although it remains 70% below its peak in the summer of 2014.
The rise is being put down to talks taking place between oil-producing countries in an effort to curb production.
No concrete agreements have been reached, but a number of key oil-producing nations are meeting in Moscow this month.
Meanwhile, ratings agency Fitch said oil prices would remain at an average of $35 a barrel this year.