NATO announced on Friday that that the two US soldiers were killed in an insurgent attack.
The alliance, however, did not disclose the exact location of the incident.
The UK’s Ministry of Defense, meanwhile, said the British soldier was killed in a blast while providing security for a clearance operation.
The deaths bring the number of foreign troops killed in Afghanistan so far in this year to 272.
Last week was the bloodiest for the foreign forces with at least 30 troop fatalities.
The militants have increased their attacks on the NATO forces in retaliation to the alliance’s plans to launch another attack against the Taliban in Kandahar.
NATO currently has about 130,000 soldiers in the war-torn country. The US has plans to deploy 30,000 extra troops by August.
The rising number of casualties has increased opposition to the Afghan war in the member states of the western military alliance.
The 2001 US-led invasion was launched with the objective of brining peace and stability to Afghanistan. Nine years on, however, Taliban militancy has reached new heights and civilians continue to pay the price.
Source: Press TV