The United States on Thursday launched a major operation against the Taliban in southern Afghanistan, according to military officials.
The operation comes in the wake of a similar operation by British troops last week, and is the largest since the US moved additional troops to the strife-torn country earlier this year.
Operation Khanjar -- 'strike of the sword' involves 4,000 US troops, mostly Marines, and 650 soldiers from Afghanistan as well as the police. It was launched in the Helmand River valley.
The operation is the first major initiative by the US military in the country after General Stanley McChrystal took over as the allied commander.
A senior Pentagon official observed that the US forces would be 'going into the most troubled area of Afghanistan', as Helmand has witnessed heavy fighting and intense violence by Taliban militants, according to a CNN report.
Over 25 soldiers from both US and British military have been killed in Helmand Province this year.
Sources suggested that the operation was not an 'offensive push' but an effort by the US military to take over a Taliban-held area and keep the militants away, said the CNN.
The eight-year-old war on terror, which started after the 9/11 attacks, had received a new lease of life when the Obama administration moved nearly 21,000 US troops to Afghanistan.