SHIKARPUR, Pakistan — Victims of Pakistan's deadly floods mobbed relief trucks carrying food and authorities in the northwest warned of famine unless the region's farmers got immediate help with planting new crops.The floods began three weeks ago, but there is little sign conditions are improving for some 20 million people — or one in nine Pakistanis — who are affected. Tens of thousands of villages remain under water, and officials feared that more flooding could be on the way.The already shaky and unpopular government has been sorely tested by the disaster, which is complicating the U.S.-backed campaign against Islamist militants. The international community is rushing water, medicine, shelter and aid workers to the country, but aid groups and the British government have complained that the response has been too slow and not generous enough.President Asif Ali Zardari's reputation sank to new lows after he chose to visit Europe on a state visit as the crisis unfolded. In a meeting with local aid groups, Zardari acknowledged Tuesday that the disaster response had not been very good."Yes, the situation could have been better. Yes, the arrangements could have been made better. Yes, everything could have been better," he said. "We have to move forward despite whatever criticism we get."The UN appealed last week for $459 million for immediate relief efforts and has received 40 percent of that so far, said U.N. spokesman Maurizio Giuliano. Another $43 million has been pledged.