In the past few years the Transportation Security Administration (TSA) has strengthened its program for assessing security at foreign airports with flights into the U.S. although it needs better data to better understand shortcomings in some areas, a government auditor told a House panel on Tuesday.

Despite TSA’s efforts, some overseas airports aren’t able to meet baseline international security standards, which is why the agency needs better data management for its program that assesses security at last point of departure (LPD) airports, Jennifer Grover, director of Homeland Security and Justice at GAO, said.capitol

Based on analysis of five years of TSA data, “I can say that airports in certain regions are more likely to fall short of the standards and that some of the ICAO standards tend to be more challenging to implement than others,” Grover told the House Homeland Security Committee panel that deals with transportation security. “Given the ongoing vulnerabilities that remain in some LPD airports, TSA should pursue improved data management to better monitor the relative effectiveness of the wide variety of different approaches that they have available to them as well as the aviation security environment as a whole.”

ICAO stands for International Civil Aviation Organization and is a United Nation’s entity focused on reaching consensus on international civil aviation standards and best practices. Grover said that TSA considers the results of GAO’s analysis of the agency’s data to be sensitive so GAO isn’t disclosing the regional variations and specific deficiencies. GAO will release a report on its analysis, she said.

Rep. John Katko (R-N.Y.), chairman of the subcommittee, said at the outset of Tuesday’s, that some foreign airports “are receiving passing grades based on ICAO standards” and that “DHS must do all it can to raise these international standards and ensure their enforcement.” The hearing examined the Department of Homeland Security’s efforts to improve aviation security globally.

Grover said TSA is inconsistent in its data tracking of foreign airport security deficiencies. She pointed out that a review of TSA’s data for 2016 showed that “70 percent of the data on root causes and corrective actions was blank.”

Completing the required data entries and being more specific with the data would allow TSA to better measure how successful it is helping with security on an airport by airport basis and give it “better visibility on the state of security at LPD airports worldwide,” Grover said.

Although GAO’s report hasn’t been published, TSA has reviewed it and concurs with the audit’s recommendations, Craig Lynes, director of Global Compliance at TSA, told the panel.

The improvements TSA has made in its foreign airport assessment program include risk based operations, more targeted assessments and better scoring, and new approaches to data analysis, Grover said. She also highlighted tools the agency uses to help address deficiencies, including spot recommendations, training, technical consultations and providing equipment.

TSA also works with air carriers operating from LPD airports to close security gaps, she said.

Lynes highlighted steps that TSA took this summer, first for 10 airports in the Middle East and North Africa, and then later for all flights into the U.S., requiring enhanced security measures, with the goal “to significantly raise the aviation security global baseline in a very short period of time.”