President Trump’s trade policies have helped to push down oil prices while raising the costs of materials for oil and gas companies.

Chevron said net income fell by just over a third to $3.5bn in the first quarter, down from $5.5bn a year earlier, and slightly below analysts’ consensus estimates. Revenues fell to $47.6bn, down from $48.7bn a year earlier, as its global production remained flat.

The major oil companies’ results were hurt by narrow refining margins, lower oil prices and rising costs.