TORONTO — World leaders, facing serious differences over the best way to nurture a fragile global recovery, are agreeing to disagree in a variety of key areas. Even before the economic talks were to begin over lunch today, the leaders engaged in a series of dueling letters and interviews that exposed their conflicts.

The three days of talks were starting at a lakeside resort north of Toronto where the Group of Eight countries — the United States, Japan, Germany, France, Britain, Italy, Canada and Russia — will discuss proposals to increase support for maternal and child health care in poor nations and hold an outreach meeting with leaders of seven African nations.

The G-8 will also spend time exchanging views on hot-button issues, such as Iran's nuclear program and possible sanctions on North Korea following the sinking of a South Korean warship.

The countries were also struggling to resolve major differences over reform of the financial system, including setting tougher standards for bank capital, the cushion banks must hold to cover losses, and over whether countries should impose taxes on banks to reimburse taxpayers for the bank bailouts.