KABUL, May 19 (RIA Novosti) - The recently appointed U.S. ambassador to Afghanistan joined President Hamid Karzai on a trip Tuesday to the western province of Farah to meet with relatives of those killed during a recent U.S.-Taliban clash.

According to the Afghan government, some 140 civilians were killed on May 4-5 in Farah's Bala Buluk district following U.S.-led airstrikes in the district against suspected Taliban militants.

"I have been telling the foreigners for five years that there is no terrorism in the houses of peaceful Afghan people, in Afghan villages... I am telling them to go and destroy bases of terrorists, but not the houses of peaceful civilians," Karzai told some 1,000 people gathered in a mosque in the capital of Farah district.

Ambassador Karl Eikenberry's decision to join Karzai on the trip to Farah was a surprise as the U.S. military still disputes the number of people killed in the Bala Buluk district.

"I assure the people of Afghanistan that the United States will work tirelessly with your government, army and police to find ways to reduce the price paid by civilians and avoid tragedies like what occurred in Bala Buluk," Eikenberry was quoted by international media as saying.

On May 7 hundreds of Afghans took to the streets protesting civilian deaths in Farah. Protesters threw stones at government buildings, chanted anti-American slogans and demanded the arrest of those guilty of the massacre.

The Afghan massacre has been criticized by international organizations, including the Red Cross. Following a meeting with Karzai in Washington two weeks ago, President Barack Obama expressed U.S. regret over the incident.

Afghanistan's government has been increasingly critical of U.S.-led strikes that have led to major civilian losses. According to the United Nations, 552 civilians were killed by NATO airstrikes in Afghanistan in 2008.