The Group of Eight nations Saturday said conditions in Gaza under an Israeli blockade were “not sustainable and must be changed.” They pressed Israel and the Palestinians to work for direct peace talks. The G8 nations also deplored what it said was North Korea's sinking of a South Korean warship and urged Pyongyang and Tehran to halt atomic sabre-rattling which has set the world on edge. The G8 closed its annual summit with a strongly worded statement accusing Pyongyang of stoking dangerous tensions that could spread far beyond northeast Asia. “Such an incident is a challenge to peace and security in the region and beyond,” the G8 final communique said at the end of a two-day meeting in Huntsville, Ontario, north of Toronto. It also called on all nations to fully implement new UN sanctions on Tehran over its atomic program. “We are profoundly concerned by Iran's continued lack of transparency regarding its nuclear activities and its stated intention to continue and expand enriching uranium, including to nearly 20 percent,” the communique said. The G8 leaders agreed that Afghan President Hamid Karzai would have an “important opportunity” at a conference next month in Kabul to show he is making good on pledges to improve governance and security as the nearly nine-year-old war in Afghanistan enters a pivotal phase.