BP chief executive Bob Dudley said on Tuesday the oil company's operations in Iraq were so far unaffected by violence in the country.
"We are just very vigilant in Iraq. Non-essential production people have left but operations continue," he told reporters on the sidelines of an energy conference in Moscow.
Last week, militants from the Islamic State in Iraq and the
Levant (ISIL) overran the northern city of Mosul and have since pressed south towards Baghdad in an onslaught against the Shi'ite-led government.
Dudley said BP's assets were a "long way from the troubles" in the south of the country, near Basra.
Along with the China National Petroleum Corporation (CNPC), BP operates under a technical service contract with Iraq's state-owned South Oil Company to boost production from the Rumaila oilfield.
Under the contract, BP and its partners aim to increase plateau production to 2.85 million barrels per day at Rumaila in the second half of the next decade.
Almost all Western oil majors work with Baghdad on joint projects including Exxon Mobil, BP, Royal Dutch Shell, ENI, Russia's Gazprom Neft, Lukoil and Chinese firms.
Asked if he was concerned about the Iraqi government's control over the country, Dudley said: "The people we are dealing with appear to be very much in control of the oil communications that we have."
Vagit Alekperov, chief executive of Lukoil which operates the West Qurna-2 oil field, told reporters on Monday his company had boosted security at the field but that the company did not feel that the project was under threat at the moment.