A top Canadian official visiting Washington, D.C. to lobby for the Keystone XL oil sands pipeline said Monday that Canada wants to work with the U.S. to curb carbon emissions from oil development.

Joe Oliver, Canada’s Minister of Natural Resources, spoke to reporters after meeting with U.S. Energy Secretary Ernest Moniz on various energy topics, including the Keystone XL pipeline that’s under State Department review.

Oliver, at a press briefing, refused to discuss reports that Canadian Prime Minister Stephen Harper recently wrote to President Obama urging joint action to reduce oil-and-sector emissions in an effort to gain approval of Keystone.

But he made clear that Canada is open to new efforts as it lobbies U.S. officials in favor of TransCanada Corp.’s project, which would bring oil from Alberta’s oil sands to Gulf Coast refineries.