Global supply problems could offset high production from the Organization of Petroleum Exporting Countries, augmenting crude prices and exchange traded funds that track oil.

The U.S. Oil Fund (NYSEArca: USO) is up 11.5% over the past three months.

According to the International Energy Agency, despite Saudi Arabian production hitting a 30-year high and OPEC producing at a three-year high in February, supply troubles from Canada to South Sudan has offset the extra supply, reports James Herron for The Wall Street Journal.

The IEA revealed that the supply of oil dropped 500,000 per day from countries outside of OPEC in February as a result of bad weather in the North Sea; maintenance disruptions in Canada; violence in Syria, Columbia and Yemen; and political disputes between South Sudan and Sudan.

Additionally, the agency mentions the heightened impact of sanctions against Iranian oil exports. [Oil ETFs Rally on Supply Worries]

“Exports of Iranian crude could ultimately be curtailed by around 800,000 to 1 million barrels a day from midyear onwards,” the IEA said. “Almost all of Iran’s buyers will inevitably scale back volumes in order to avoid falling foul of sanctions.”

OPEC countries could raise output to cover Iran, but pushing spare oil supply capacity “hinges on Iraq, Libya and Nigeria, which is a trio of fairly unstable countries,” Samuel Ciszuk of KBC Energy Economics said in the article.