The most senior British military commander in Afghanistan today described the situation in the country as "close to anarchy" with feuding foreign agencies and unethical private security companies compounding problems caused by local corruption.

The stark warning came from Lieutenant General David Richards, head of Nato's international security force in Afghanistan, who warned that western forces there were short of equipment and were "running out of time" if they were going to meet the expectations of the Afghan people.

The assumption within Nato countries had been that the environment in Afghanistan after the defeat of the Taliban in 2002 would be benign, Gen Richards said. "That is clearly not the case," he said today. He referred to disputes between tribes crossing the border with Pakistan, and divisions between religious and secular factions cynically manipulated by "anarcho-warlords".

Corrupt local officials were fuelling the problem and Nato's provincial reconstruction teams in Afghanistan were sending out conflicting signals, Gen Richards told a conference at the Royal United Services Institute in London. "The situation is close to anarchy," he said, referring in particular to what he called "the lack of unity between different agencies".

He described "poorly regulated private security companies" as unethical and "all too ready to discharge firearms". Nato forces in Afghanistan were short of equipment, notably aircraft, but also of medical evacuation systems and life-saving equipment.

Officials said later that France and Turkey had sent troops to Kabul but without any helicopters to support them.

Gen Richards will also take command of the 4,500-strong British brigade in Helmand province at the heart of the hostile, poppy-growing south of the country when it comes under Nato's overall authority. He said today that Nato "could not afford not to succeed" in its attempt to bring long-term stability to Afghanistan and build up the country's national army and security forces. He described the mission as a watershed for Nato, taking on "land combat operations for the first time in its history".

The picture Gen Richards painted today contrasted markedly with optimistic comments by ministers when they agreed earlier this month to send reinforcements to southern Afghanistan at the request of British commanders there. Many of those will be engineers with the task of appealing to Afghan "hearts and minds" by repairing the infrastructure, including irrigation systems.

Gen Richards said today that was a priority. How to eradicate opium poppies - an issue repeatedly highlighted by ministers - was a problem that could only be tackled later.

General Sir Mike Jackson, the head of the British army, said recently: "To physically eradicate [opium poppies] before all the conditions are right seems to me to be counter-productive." The government admits that Helmand province is about to produce a bumper poppy crop and is now probably the biggest single source of heroin in the world. Ministers are concerned about criticism the government will face if planting over the next few months for next year's crop - in an area patrolled by British troops - is not significantly reduced.

Kim Howells, the Foreign Office minister responsible for Afghanistan, told the Guardian that the immediate target had to be the biggest poppy cultivators and dealers who control the £1bn-plus Afghan drug trade.

The strategy should be: "Go for the fat cats, very wealthy farmers, the movers and shakers of the drug trade" and their laboratories, he said. Asked about the concern of British military commanders that by depriving farmers - and warlords - of a lucrative crop, poppy eradication would feed the insurgency, Mr Howells admitted: "It's a big problem for us."