North Korea on Thursday called for an "all-out battle" against record temperatures that threaten crops in a country already grappling with tough international sanctions over its nuclear weapons program. The resulting drought has brought an "unprecedented natural disaster," the isolated nation said, warning against crop damage that could savage its farm-reliant economy, battered by sanctions despite recent diplomatic overtures. "This high-temperature phenomenon is the largest, unprecedented natural disaster, but not an obstacle we cannot overcome," the North's Rodong Sinmun said, urging that "all capabilities" be mobilized to fight the extended dry spell. Temperatures have topped a record 40 degrees in some regions since late July, and crops such as rice and maize have begun to show signs of damage, the mouthpiece of the ruling Workers' Party said in a front-page commentary. "Whether the current good crop conditions, for which the whole nation has made unsparing investment and sweated until now, will lead to a bumper year in the autumn hinges on how we overcome the heat and drought," it added. Similar past warnings in state media have served to drum up foreign assistance and boost domestic unity.