More than half the U.S. diplomatic posts overseas may not fully meet security standards, a senior U.S. official told a hearing on Thursday that follows an attack on the mission in Benghazi in which the U.S. ambassador and three other Americans died.

Pat Kennedy, the under secretary of state for management at the State Department, told a House of Representatives appropriations subcommittee that the United States had a diplomatic presence at 283 locations around the world.

He said 97 safe and secure facilities had been completed since the 1999 passage of a U.S. law authorizing additional funding for security upgrades, including 70 full replacements of embassies or consulates, as well as some building of Marine guard quarters and office annexes.

“There remain approximately 158 posts that have facilities that may not fully meet current security standards,” he said.