Image copyright AP Image caption The death is the second of a US service member this year

A US service member has been killed in Afghanistan, the first combat death there since January, officials said.

The service member was killed by improvised explosive device (IED) while on patrol near the city of Lashkar Gar in Helmand Province.

A second US service member and six Afghan soldiers were also injured in the operation.

US officials have not released the service member's name pending notification of family.

"We are deeply saddened by this loss, but remain committed to helping our Afghan partners provide a brighter future for themselves and their children," said General John W Nicholson, commander of US and NATO forces in the country.

The patrol triggered the IED while the service member was "conducting Train, Advise, Assist activities with Afghan counterparts" in the provincial capital, according to a US Forces Afghanistan statement.

The wounded service member was in stable condition, officials said.

In January, Army Green Beret Staff Sgt Matthew McClintock died after a firefight near Marjah in the restive Helmand Province.

The 30-year-old was assisting Afghan Special Operations troops during an offensive launched by Taliban members when he was killed.

Pentagon officials confirmed on Monday that the US has deployed 100 troops to Lashkar Gar to train, advise and assist local Afghan police.

Pentagon Press Secretary Peter Cook said the deployment was temporary and troops would "return to their base at some point."

President Barack Obama announced last month the US would maintain 8,400 US troops in Afghanistan, instead of reducing the number to 5,500 as planned, in an effort to combat mounting attacks by the Taliban.

The US ended major combat operations in Afghanistan in 2014.