Oil futures settled lower on Tuesday after President Donald Trump fired National Security Advisor John Bolton, boosting the chance of U.S. talks with Iran that could lead to the U.S. lifting oil sanctions on Tehran, adding more oil on the market. Trump and Iranian President Hassan Rouhani could have a meeting later this month at the United Nations, Secretary of State Mike Pompeo said Tuesday. Meanwhile, in a monthly report, the Energy Information Administration cut its 2019 and 2020 price forecasts for West Texas Intermediate and Brent crude. October WTI oil CLV19, -0.93% fell 45 cents, or 0.8%, to settle at $57.40 a barrel on the New York Mercantile Exchange.