WASHINGTON (Agencies) - US public perceptions of Pakistan and Afghanistan have sunk to new lows as the war campaign against extremism approaches its 10th year, a poll said. Some 14 percent of Americans have a favourable view of Afghanistan and 82 percent hold a negative review, the Gallup poll said. For Pakistan, 18 percent saw the country favourably and 76 percent viewed it unfavourably. The views were the most negative since Gallup began asking the question. Opinion about the two nations peaked in 2005, when upwards of 40 percent of Americans saw both Afghanistan and Pakistan in a positive light. Separate polls have shown low US support for the war in Afghanistan, as well as strongly unfavourable views of the United States in Pakistan. The Gallup poll, which surveyed 1,015 US adults, also found that US opinion of South Korea has reached a new high, with 65 percent seeing the Asian ally favourably. US relations with South Korea have improved markedly since conservative President Lee Myung-Bak took office in 2008. The United States and South Korea have finalised a free trade deal first negotiated by earlier administrations. The most popular Asian nation among the US public remained Japan, with 80 percent of Americans holding a favourable view, in line with findings in recent years. Americans had higher opinions only of Canada, which 92 percent saw favourably, along with Britain and Germany. Despite a year of friction with China on trade and other issues, US perceptions rose slightly, with 47 percent of Americans seeing the rising Asian power favourably, compared with 42 percent a year earlier. The worst-viewed nations were North Korea and Iran, with only 11 percent of Americans seeing each country in a favourable light. The poll had a margin of error of four percentage points.