A U.S. Foreign Service officer was killed and four others wounded in Afghanistan while carrying out a goodwill mission in the eastern part of the country.
"She was everything a foreign service officer should be: smart, capable, eager to serve, and deeply committed to our country and the difference she was making for the Afghan people," Kerry said of the slain official.
"She tragically gave her young life working to give young Afghans the opportunity to have a better future," he added in a statement issued Saturday.
The State Department has yet to release the officer's name.
Three American soldiers providing security for the convoy were also killed in the bombing.
Of the four wounded State Department officials, one remains in critical condition.
Another U.S. soldier was killed in Eastern Afghanistan on Saturday during a Taliban attack against American forces in the region.
Both strikes came on the same day as chairman of the Joint Chiefs of Staff, Gen. Martin Dempsey, arrived in Afghanistan to meet with U.S., NATO and Afghan leaders.
Dempsey’s visit is to assess the ongoing effort to end America's war in the country within the next year.
For his part, Kerry has "been in close touch" with President Obama, Defense Secretary Chuck HagelChuck HagelLobbying World Ex-Dem leader: Clinton should include GOP in Cabinet Even Steven: How would a 50-50 Senate operate? MORE and senior department officials regarding both strikes.
The State Department chief also spoke U.S. Ambassador to Afghanistan James Cunningham in Kabul shortly after the bombing.
"We will all keep in close contact as we learn more facts about this attack and the brave people who were killed and wounded. We are also in contact with the families of those injured," Kerry added.
The casualties in Saturday's attack were the first ones suffered by the State Department since last September's deadly terrorist assault on the U.S Consulate in Benghazi, Libya.
U.S. Ambassador Chris Stevens and four other Americans were killed in that attack.