Washington, Aug 18 (DPA) Days before Afghans go to the polls to cast ballots in historical presidential elections, US President Barack Obama warned the fight in the country will be long and difficult.

Speaking to the Veterans of Foreign Wars in Phoenix, Arizona, Obama said the US must remain committed to Afghanistan's security future as well as the development of its economy and government.

'There will be more difficult days ahead,' Obama said. 'The insurgency in Afghanistan didn't just happen overnight. And we won't defeat it overnight. This will not be quick. This will not be easy.'

The conflict is among Obama's top foreign policy priorities as he winds down the war in Iraq and steps up US efforts in Afghanistan. US Marines last month launched a major assault against the Taliban in Helmand province.

The increase in fighting has taken the largest monthly death toll of American solders since the beginning of the war in October 2001.