Group of Eight leaders had to soften a statement urging Israel and the Palestinians to return to negotiations because Canada objected to a specific mention of 1967 borders, diplomats said on Friday.
Canada's right-leaning Conservative government has adopted a staunchly pro-Israel position in international negotiations since coming to power in 2006, with Prime Minister Stephen Harper saying Canada will back Israel whatever the cost.
Diplomats involved in Middle East discussions at the G8 summit said Ottawa had insisted that no mention of Israel's pre-1967 borders be made in the leaders' final communiqué, even though most of the other leaders wanted a mention.
"The Canadians were really very adamant, even though Obama expressly referred to 1967 borders in his speech last week," one European diplomat said.
A spokesman for Harper would not comment on the line Canada had taken, saying only that the final communiqué would make positions clear.
In the final communiqué, a copy of which was obtained by Reuters, the leaders call for the immediate resumption of peace talks but do not mention 1967, the year Israel seized the West Bank and Gaza from Jordan and Egypt during the Six-Day War.
"Negotiations are the only way toward a comprehensive and lasting resolution to the conflict," the communiqué said.
"The framework for these negotiations is well known. We urge both parties to return to substantive talks with a view to concluding a framework agreement on all final status issues.
"To that effect, we express our strong support for the vision of Israeli-Palestinian peace outlined by President Obama on May 19, 2011."
In his speech last week, Obama said pre-1967 borders should be a basis of talks to achieve a negotiated settlement, although he also acknowledged any agreement would ultimately involve land swaps on either side of the border.
That position was rejected by Prime Minister Benjamin Netanyahu, who said Israel would be indefensible if it returned entirely to the borders that existed before 1967.
Canada's strong backing for Israel was cited by diplomats last year as one reason why Ottawa failed to win a rotating two-year seat on the United Nations Security Council.
Harper has made is position on Israel very clear, saying last year: "When Israel, the only country in the world whose very existence is under attack, is consistently and conspicuously singled out for condemnation, I believe we are morally obligated to take a stand."