NATO says the soldiers were killed in an IED blast near the central city of Ghazni. Meanwhile, an international conference on Afghanistan is underway in the Swiss city to discuss how to end the 17-year war.
Three US soldiers were killed and three wounded by a bomb in Afghanistan on Tuesday, NATO said, taking the death toll of US service personnel in the country this year to 12, as Afghan leaders and international diplomats discussed the war in Geneva.
NATO's Resolute Support mission would not immediately release any details about the soldiers, but said they had been killed when an improvised explosive device (IED) detonated near Ghazni city in central Afghanistan.
The attack was claimed by Afghan Taliban.
An American contractor was also wounded, NATO said, adding that the four wounded in the blast were receiving medical care.
The casualties come after another US soldier was killed in Afghanistan's Nimroz province on Saturday.
More than 2,200 American soldiers have been killed in Afghanistan since the 2001 US-led invasion that toppled the Afghan Taliban from power.
Casualties on rise
The number of American casualties has fallen dramatically since the end of 2014 when Afghan forces took over from US-led NATO combat troops to secure the country.
Since the start of 2015, 58 Americans have been killed, President Ashraf Ghani said earlier this month.
In the same time period, nearly 30,000 Afghan police and soldiers have died, Ghani said — a figure much higher than any previously acknowledged.
The shocking mortality rate, which some experts warn is unsustainable, has sent already shaky morale to new lows.
The Taliban has intensified attacks on Afghan forces even as the United States ratchets up efforts to engage the fighters in peace talks.
#Afghanistan's first lady Lula Ghani and Chief Executive Officer Dr. Abdallah join the panel on #refugees under the theme "People on the Move" moderated by UNHCR Philippo Grandi on the 1st day of #Geneva Ministerial Conference on Afghanistan. #GVAfghanistan2018 #GCAfghanistan2018 pic.twitter.com/JkYcMNzcsv— OIC (@OIC_OCI) November 27, 2018
In the meantime, Afghan leaders and international diplomats meet in Geneva on Tuesday to evaluate whether strategies and aid offered to Afghanistan are helping resolve the quagmire created by the 17-year war, paving way for the withdrawal of foreign troops.
The two-day conference on Afghanistan, jointly hosted by the Afghan government and the United Nations comes at a time when US President Donald Trump's administration is actively seeking a peace deal with the Taliban.
Diplomats said much of the focus will be on side meetings, where officials from Afghanistan and regional and Western countries will have a chance to assess the efforts of US peace envoy Zalmay Khalilzad.
Afghans marry off children – UN
With a devastating drought worsening an already horrendous humanitarian situation in Afghanistan, parents are increasingly compelled to "sell" young daughters into marriage to pay off debt or buy food, the UN said on Tuesday.
In the drought-hit Herat and Badghis provinces of Afghanistan, the UN children's agency estimates that at least 161 children between the ages of one month and 16 years were "sold" over just a four-month period.
"The situation of children is dire in Afghanistan," UNICEF spokeswoman Alison Parker told reporters in Geneva.
Speaking as an international conference on Afghanistan got underway in the Swiss city, Parker said the children in the July to October survey were "either being betrothed, married or ... sold because their parents are in debt."