Saudi Arabia and Kuwait halted production at a jointly run oil field, known as Khafji, this week due to environmental concerns, people familiar with the matter said Sunday. The field, located in the neutral zone between the two countries, was producing around 300,000 barrels of oil a day before it was temporarily shut down, the people said. It will resume operations once it is compliant with emissions standards issued by the Saudi Presidency of Meteorology and Environment, they said. Output in the neutral zone between Saudi Arabia and Kuwait has plummeted in recent months from 600,000 barrels a day to around 300,000, industry officials have said. The Khafji field produces far more oil than the neutral zone’s other fields.