The $12-billion project seeks to connect more than one million barrels of western crude a day to oil refineries in Eastern Canada.
Ontario Premier Kathleen Wynne and Quebec Premier Philippe Couillard said last week that greenhouse gas emissions must be considered in the development of the project.
Wynne also wants assurances there will be consultations with First Nations and other communities in the path of the pipeline, an emergency response plan, and guarantees that Ontario's current supply of natural gas is secure.
Premier Brad Wall says a rigorous National Energy Board process will ensure the project is up to environmental and safety standards.
He adds that he believes the premiers from Ontario and Quebec are creating "unnecessary barriers" to the project, which he calls straightforward.
The premier of New Brunswick says stipulations for the Ontario government's support of the proposed Energy East Pipeline are reasonable and achievable.
The chairman of the National Energy Board has said climate change policy is not within its purview and it doesn't intend for its hearings to become bogged down in that debate.