Career diplomats told Congress Wednesday the US mission in Libya failed to meet crucial security standards ahead of last year\'s terror acts there, as the White House accused Republicans of politicizing the Benghazi attacks. Deputy chief of mission Gregory Hicks, the first US official on the ground during the attacks to speak publicly about what happened, provided chilling details about the events in Libya on September 11, 2012 that left four Americans dead, including ambassador Christopher Stevens. He also testified that he has been pressured by administration figures, including senior officials at the State Department, to stop questioning the US handling of the attacks. Eric Nordstrom, the regional security officer at the US Embassy in Tripoli in the months before the Benghazi attack, also said senior State Department officials were aware of security shortcomings, and it was \"inexplicable\" that their actions were not reviewed more thoroughly. The testimony by Hicks, Nordstrom, and another US official -- whom Republican lawmakers have described as \"whistleblowers\" -- is the latest in a months-long series of hearings and studies that have put the attacks and the US response under a microscope. Republicans have hammered President Barack Obama over the attacks, accusing the White House of misleading Americans in the run up to November\'s presidential election by saying the attack began as a spontaneous protest over an anti-Muslim video. The Obama administration, which later acknowledged that the attack was planned in advance, attributed the initial account to confusion about what was happening on the ground. But Hicks said it was clear from the outset last September that an attack was in progress. Among his recollection of events was the final call from Stevens to him before the ambassador died, in which Stevens made no mention of any demonstration, simply telling him \"Greg, we\'re under attack.\" In a lengthy, wide-ranging hearing before the House Government Oversight Committee, lawmakers also were told of how senior State Department officials ordered staff to occupy the buildings in Benghazi despite security shortcomings in a US mission rated among the most dangerous in the world. Of 264 overseas US diplomatic posts, \"our posts in Benghazi and Tripoli were two of the 14 posts rated either high or critical in all of the threat categories on SETL (the Security Environment Threat List),\" Nordstrom said. They were also \"the only two facilities that met no OSPB (Overseas Security Policy Board) or SECCA (Secure Embassy Construction and Counterterrorism Act) standards.\" Nordstrom said that despite the structures not meeting accepted standards, diplomatic security personnel and building operations officials told him the undersecretary of state for management \"authorized occupancy of the buildings \'as is\'.\" Hicks also said he was \"stunned\" and \"embarrassed\" when Washington\'s UN Ambassador Susan Rice told five Sunday talk shows shortly after the attack that it was a spontaneous uprising following a demonstration against the US mission due to an anti-Islamic video. Hicks said he spoke with acting assistant secretary of state Beth Jones about why Rice mentioned a demonstration, \"when the embassy reported only an attack.\" Shortly afterward, Hicks said, he was pressured to tone down his criticism. \"The sense I got was that I needed to stop my questioning,\" he said. He also said he was kept on an unreasonably tight leash by US administration lawyers when Republican congressman Jason Chaffetz visited Libya after the attacks, and was told not to allow himself \"to be personally interviewed by Congressman Chaffetz.\" The White House argued Wednesday that all the circumstances of the attack had been probed by the ARB and recommendations rising from identified shortcomings had been acted upon. \"This is a subject that has, from its beginning, been subject to attempts to politicize it by Republicans, when in fact what happened in Benghazi was a tragedy,\" White House spokesman Jay Carney said. \"The president has been committed from day one to two things: making sure that those who are responsible for the deaths of four Americans are found and brought to justice and that we do everything we need to do to ensure that this kind of attack cannot happen again.\"