State department officials say Mr Kerry's appearance at the oversight panel should mean he will not need to testify in front of the recently-formed Benghazi select committee.
He is scheduled to testify on 12 June.
A US ambassador and three others were killed after an assault on the Libyan diplomatic post in September 2012.
Republicans have argued the Democratic Obama administration misled the public on the nature of the attack.
Democrats in the US Congress have named five representatives to a special panel on the Benghazi attacks despite arguing it is motivated by Republican politics.
Mr Kerry, who was not secretary at the time, had previously been subpoenaed by the oversight committee to appear in late May, the letter said, but could not attend due to the Ukrainian crisis.
"We believe there are witnesses better suited to answer questions regarding the department's response to congressional investigations of the Benghazi attacks," the letter, dated Friday, reads.
"However in the interest of accommodations and to resolve once and for all any outstanding, relevant questions, the secretary is prepared to appear before the committee."
A separate select committee on Benghazi with the authorisation to operate until the end of the year was approved on a largely party-line vote.
Michael Steel, a spokesman for House Speaker John Boehner, told broadcaster NBC the decision whether to call Mr Kerry to testify at the select committee would be made later.
"We're glad Secretary Kerry will appear at oversight," Mr Steel said. "Whether he will also be asked appear before the Select Committee will be a decision for Chairman Gowdy in the future."
US Secretary of State John Kerry will testify in front of a House panel about the deadly Benghazi attacks, according to a letter obtained by the BBC.