"The declaration sets out measures to help protect the arctic's ecosystems during oil and gas exploration and development activities to be undertaken by Rosneft and its partners," Exxon said in a statement.
Warmer climate trends have left arctic areas ice-free for longer periods of time, exposing areas that made contain oil and natural gas resources. Environmental groups have expressed concern over the pristine conditions in arctic regions.
In August, both companies signed a sweeping deal that included development in parts of the Black Sea and the South Kara Sea in the Russian arctic. There may be as much as 85 billion barrels of oil in the Kara Sea. By September, they had planned a feasibility study for a platform capable of exploring shallow arctic waters.
"We seek to manage the impact on the environment wherever we operate through continuous improvements in technology and operational procedures," Tillerson said.