The loss of more than 100 foreign troops in the Afghan war in June serves as a grim reminder to the international community of why Afghanistan is known as the “graveyard of empires”.

At 102, the June toll almost tripled the number of US and NATO soldiers killed in May, making the month the deadliest since the war began in 2001.

The new commander of the Afghan war, US General David Petraeus, warned this week the fighting will get tougher before the situation on the ground improves.

Petraeus, speaking on Tuesday at a senate hearing on his nomination to replace his sacked predecessor General Stanley McChrystal, said foreign troops in Afghanistan were fighting an “industrial-strength insurgency”. 

“My sense is that the tough fighting will continue; indeed it may get more intense in the next few months,” he said.

The latest death was announced on Wednesday by NATO’s International Security Assistance Force (ISAF), which said a soldier had died in an attack in eastern Afghanistan.

While it gave no details of the circumstances, nor the nationality of the soldier, a major anti-Taliban operation is under way in the eastern province of Kunar involving hundreds of NATO and Afghan troops.

Just two months ago, in April, the number of foreign soldiers who died in the country was 20, according to an AFP tally based on that kept by the independent icasualties.org website.

The previous deadliest month the allied force suffered in its efforts to quell the Taliban insurgency was August last year, when 77 soldiers lost their lives.

In total 322 foreign soldiers have died so far this year, compared with a toll for all 2009 of 520.

Afghanistan is in the grip of an Islamist insurgency that has gained strength every year since the Taliban regrouped a few months after their brutal regime was overthrown by a US-led invasion in retaliation for the September 11 attacks.

The Taliban authorities had harboured Al-Qaeda, giving the organisation led by Osama bin Laden a safe haven, from where they planned the devastating 2001 attacks on the US that killed more than 3,000 people.

Western leaders and military commanders say that only by meeting the Taliban on the battlefield in Afghanistan can they safeguard their own people from further attacks.

But they concede the escalating death toll of foreign soldiers — most of them American — is attributable in part to intensified military operations against the Taliban in their southern strongholds.

“It’s a tough time we’re in,” said German army General Josef Blotz, a spokesman for ISAF.

“We are in the arena, there’s no way out now, we have to stay on, we have to fight this campaign,” he told reporters this week.

The US and NATO have 140,000 troops in Afghanistan, set to peak at 150,000 by August, completing the “surge” ordered up by US President Barack Obama as part of a counter-insurgency strategy to speed the end of the war.

About 15,000 US, NATO and Afghan troops earlier this year went to Marjah, a poppy-producing region of southern Helmand province, long under the control of the Taliban.

The massive operation aimed to flush out Taliban insurgents in what commanders said was the biggest military push against the rebels since 2001. Governance was set to follow in the immediate wake of military success.

But fighting continues more than four months later, and an even bigger strike against the Taliban in neighbouring Kandahar province, the Islamists’ heartland — has been postponed.

Nevertheless, most of the newly-deployed troops — including the 30,000 “surgers” — are heading to Kandahar and Helmand, and battles are growing in number and intensity.

This in turn is drawing insurgents — including fighters from Pakistan and other countries in the region — into those areas, leading to a commensurate leap in casualties.

“With the build-up of these new reinforcements we were able to confront the insurgency and Taliban in areas where they have not been challenged for years,” Blotz said.

“And that’s the reason that we see some more violence in these days and weeks and unfortunately this also leads to a higher casualty rate.”

Petraeus, due to arrive in Kabul at the weekend, tried to reassure the anxious Congressional hearing that the troops he will soon be commanding are making headway.

“The coalition force “has achieved progress in several locations” this year, he said.

But he warned them to brace for a “tough fight” ahead.