China is interested in making ``substantial investments leading to substantial exports'' in Canada's oil sands, McCallum told reporters in a conference call from China where he spoke with China's resource minister and attended a conference of Group of 20 finance ministers. Canada's Prime Minister Paul Martin has said the nation may seek new customers for its oil after the U.S. ignored a North American Free Trade Act ruling ordering it to change duties on softwood lumber. Alberta's oil sands, where crude-encrusted sand is strip-mined or flushed out of wells, hold the biggest oil reserves outside of Saudi Arabia. ``We are moving forward with great vigor to make this strategic partnership a reality,'' McCallum said when asked if the Nafta dispute has a bearing on the nation's overtures to China. ``Canada is entirely serious about using every means at our disposal'' to make sure the U.S. respects Nafta. The U.S. argued that the Nafta ruling didn't apply because it was superseded by a more recent decision by the U.S. International Trade Commission. The duties have stayed in place, and none of the $4 billion in levies already collected is being returned, the U.S. said. Enbridge Inc., Canada's second-biggest pipeline company, said yesterday it would build a tanker-loading facility and oil pipeline capable of carrying 400,000 barrels a day to a deepwater port on the nation's west coast. Canada currently doesn't have large exports to China because of a lack of port facilities and Chinese refineries aren't set up to process Canada's heavier grades of crude oil. PIN/BLOOMBERG