WASHINGTON (AP) — The State Department has made only limited progress in its pledge to boost the number of Marine security guards at high-threat diplomatic posts around the world, the agency’s internal watchdog said Thursday.

In a report, the department’s inspector general said efforts to increase Marine Security Guard units in at-risk embassies and consulates — a main recommendation after the deadly Sept. 11, 2012, attack on the U.S. mission in Benghazi, Libya, that killed the Ambassador Chris Stevens and three other Americans — had thus far made only “modest contributions” to that end.