WASHINGTON — Witnesses told the House Foreign Affairs subcommittee on South and Central Asia that gaps in export controls on semiconductor manufacturing equipment and specialized subcomponents are allowing China to expand its chipmaking capacity, posing national-security and economic risks.

Chairman Huizenga opened the hearing saying advanced AI and foundational chips ‘‘power everything from phones and cars to the military drones’’ on modern battlefields and urging Congress and the executive branch to close remaining export-control loopholes. Ranking Member Representative Kamlager Dove criticized the use of export controls as a bargaining chip in diplomacy and raised concerns about a reported sale of 35,000 NVIDIA Blackwell AI chips to Saudi Arabia, asking for a classified briefing.

Dean Ball, senior fellow at the Foundation for American Innovation, said the United States had successfully denied China access to the most advanced lithography machines but ‘‘has failed to deny access to something perhaps even more important, the machines that make the machines.’’ Ball urged diplomacy and consideration of the foreign direct product rule to extend U.S. controls to foreign-made items that incorporate U.S. technology.

Chris McGuire, senior fellow for China and emerging technologies at the Council on Foreign Relations, outlined five priorities including stronger controls on SME (semiconductor manufacturing equipment), leveling up allied controls (noting shortfalls in the Netherlands and Japan), countrywide restrictions on tools capable of advanced production, and expansion of extraterritorial authorities. McGuire said allied exports of functionally equivalent tools and on-site servicing have ‘‘uplifted Chinese chip making capabilities while also shifting market share away from U.S. firms.’’

Kevin Wolf, partner at Akin Gump and a former assistant secretary at the Bureau of Industry and Security (BIS), cautioned that policymakers must define loopholes precisely and weigh measures that are effective without unduly harming U.S. industry. ‘‘If something warrants control because of national security concerns … it should be controlled. If not, then not,’’ he said, emphasizing trade-offs and the need for subject-matter expertise inside BIS.

Lawmakers pressed witnesses on several recurring themes: allied backfilling (where Dutch or Japanese firms sell tools or components after U.S. firms are restricted), the limits of entity-list measures when companies can shift supply chains, the importance of servicing and maintenance (particularly for lithography tools), and vulnerabilities tied to high-bandwidth memory and other choke points.

Members also focused on enforcement and resourcing. Witnesses and legislators urged increased staffing and IT modernization at BIS, expanded overseas export-control officers to conduct end-use checks, and stronger whistleblower protections and licensing requirements to trace shipments through intermediate countries. McGuire recommended ‘‘countrywide restrictions’’ on tools used in advanced production and suggested a global licensing approach for an expanded set of countries to prevent diversion to China.

The hearing produced no formal votes or immediate policy changes. Chairman Huizenga requested written follow-up from the witnesses; members signaled bipartisan interest in legislative approaches that could include codifying foreign direct product rules, increasing BIS resources, and pursuing allied coordination.

The subcommittee adjourned after requesting additional materials for the record and noting that members may submit follow-up questions in writing.