I'm honored to serve as Assistant Secretary for Arms Control and Nonproliferation, and grateful to @POTUS and @SecRubio for their confidence. Alongside the talented professionals of the ACN bureau, we will execute @POTUS 's mission of making America safer, stronger, and more prosperous. Stay tuned for updates on our efforts!

The U.S. & Norway co-hosted the Nordic-Baltic Regional #SecurityProliferationInitiative Engagement in Oslo this week. 60 civilian, customs, and law enforcement & military leaders from 13 nations came together to sharpen counterproliferation capabilities and stop the spread of #WMD. 🌎 state.gov/releases/bureau-of…

Through Operation Economic Fury, we continue to disrupt procurement networks that support the Iranian regime’s military programs and its military activities in the region. Today the United States sanctioned 13 individuals and entities based in Iran, Belarus, and China who sought to source and purchase weapons on behalf of the Islamic Revolutionary Guard Corps.

Today, the United States sanctioned 13 individuals and entities in Iran, Belarus, and China, including Hong Kong, for supporting Iran’s weapons procurement, including efforts to acquire MANPADS. We will continue to maintain maximum pressure on Iran and disrupt networks that support its military programs. state.gov/releases/office-of…

As part of the regional FIRST workshop, Assistant Secretary Christopher Yeaw visited Atucha II nuclear power plant in Argentina. The group took a technical tour to the turbine hall, condensers, control room simulator, and other facilities.

Estados Unidos y Argentina están liderando el futuro nuclear de nuestro hemisferio🇺🇸🇦🇷. En FIRST, junto a Canadá y socios de América Latina, Japón y el Reino Unido, avanzamos una visión compartida: más innovación, más inversión y más seguridad energética. El futuro es nuclear, y lo construiremos juntos.

Hoy tuve el honor de inaugurar la conferencia regional del programa FIRST en Buenos Aires, junto a representantes del gobierno de los Estados Unidos y a delegaciones de toda América Latina y el Caribe. Que la Argentina sea sede responde a una decisión clara de este Gobierno: revalorizar el sector nuclear, tomar una posición de liderazgo en la región y allanar el camino para inversiones estratégicas en nuevas tecnologías como los Small Modular Reactors (SMR). Sobre una base de una economía ordenada y estabilidad jurídica, nuestro país aporta algo que se construye con el tiempo: más de setenta años de experiencia nuclear. Argentina domina el ciclo de combustible nuclear, opera centrales nucleares, exporta reactores de investigación y tiene una industria de proveedores calificados para toda la cadena de valor. Un inversor que mira a la Argentina encuentra un ecosistema consolidado, con ingeniería, recursos humanos formados y un regulador con trayectoria reconocida en seguridad y no proliferación. El sector nuclear atraviesa un momento bisagra y las inversiones que se determinen ahora marcarán el rumbo por mucho tiempo. Argentina tiene que ser protagonista de esa conversación a nivel regional. Eventos como este son, justamente, donde esas oportunidades empiezan a tomar forma para nuestro país.

ARGENTINA Y ESTADOS UNIDOS COORGANIZAN EN BUENOS AIRES LA CONFERENCIA FIRST SOBRE REACTORES MODULARES PEQUEÑOS (SMR) Comenzó el cuarto taller regional anual para América Latina y el Caribe del programa FIRST, coorganizado por la Comisión Nacional de Energía Atómica (CNEA) y el Departamento de Estado de los Estados Unidos, y tiene como objetivo promover el despliegue responsable de la tecnología de reactores modulares pequeños (SMR) bajo los más altos estándares internacionales de seguridad y no proliferación. Argentina se convirtió en el primer país de América Latina en incorporarse a esta iniciativa en calidad de socio durante 2025. Durante la primera jornada, el Presidente de la CNEA, Ing. Martín Porro, realizó una presentación sobre las capacidades argentinas en el campo de los SMR y la posibilidad de brindar servicios, ingeniería y asesoramiento a la región. La realización de este taller en el país consolida a la Argentina como un referente regional en el desarrollo de reactores modulares pequeños, así como también reconoce su trayectoria de más de siete décadas en el uso pacífico de la energía nuclear y su capacidad para acompañar a los programas emergentes de América Latina. La apertura de las jornadas contó con la participación del Secretario de Asuntos Nucleares argentino, Dr. Federico Ramos Napoli; el Embajador de los Estados Unidos en la Argentina, Peter Lamelas; el Subsecretario de Estado para Control de Armas y No Proliferación de Estados Unidos, Christopher T. Yeaw; y el Consejero Político de la Embajada de Canadá, Jonathan Sauvé. El taller reúne a representantes de Chile, Costa Rica, Ecuador, El Salvador, Jamaica, México, Paraguay, Perú y República Dominicana, además de las delegaciones de los países contribuyentes de la iniciativa.

It was an honor and a privilege to join forces with NNSA, the IAEA, the UK, and the people of Venezuela to see the successful completion of this important mission. We look forward to continuing our collaboration with Venezuela on the peaceful uses of nuclear technology for the peace, prosperity, and freedom of the Venezuelan people! state.gov/releases/office-of…

The United States-Azerbaijan Chamber of Commerce, in collaboration with @crdfglobal and the Azerbaijan Banks Association (@BanksAzerbaijan), successfully concluded a two-day advanced program on sanctions compliance and financial risk management for Azerbaijani banks and financial institutions. The program was supported by the Department of State (@StateDept), Office of Cooperative Threat Reduction. We extend our sincere appreciation to all participating banks, as well as their legal and compliance officers, for their insightful contributions and active engagement throughout the program. We are especially grateful to Ms. Amy Carlon, Chargé d’Affaires of the U.S. Embassy (@USEmbassyBaku), and Mr. Toghrul Aliyev, Deputy Governor of the Central Bank of the Republic of Azerbaijan (@Central_Bank_AZ), for their support and valuable remarks.

Pleased to announce the signing of the MOU Concerning Strategic Civil Nuclear Cooperation. This signing marks an important step forward in strengthening U.S.-Rwanda cooperation on civil nuclear energy.  🇺🇸🇷🇼 #InnovatingTogether #USAinRwanda  @StateACN

The U.S. National and Nuclear Risk Reduction Center held a side event at NPT RevCon explaining how, for nearly four decades, it has fulfilled the critical mission of reducing the risk of nuclear conflict that could arise from a misunderstanding or miscommunication.  This mission is as important today as it was when the Center was established in 1987.

Honored to mark Malta’s entry into the Registry Information Sharing Compact, or RISC, a key tool for maritime security and countering sanctions evasion. Malta strengthens RISC’s impact at a time when hostile states, armed robbers, hijackers, and organized crime syndicates exploit commercial maritime systems and undermine the international order. This signing marks a new high in U.S.-Malta relations. The United States values Malta’s leadership in maritime security and sanctions evasion prevention. I applaud Malta’s accession to RISC and look forward to deepening cooperation that supports our national security and Malta’s borders by strengthening information sharing and enhancing sanctions compliance.

The 🇺🇸 calls on all States parties to adopt a decision to strengthen the #NPT review process. Let's get to work and make this process function better for everyone. state.gov/wp-content/uploads…

The U.S. yesterday on Article VI at NPTRevCon, "The one message I want to leave everyone with here today is that the United States is ready to pursue negotiations in good faith." state.gov/wp-content/uploads…

Regional security challenges directly impact the integrity of the #NPT, and addressing these challenges through transparency, compliance, and good-faith dialogue remains essential to our collective security. state.gov/wp-content/uploads…

We're ready for the next era of arms control—but we can't do it alone. Other countries have a responsibility to help ensure strategic stability. We call on every delegation in this room to join us in encouraging China and Russia to come to the table and take action without further delay. state.gov/wp-content/uploads…

The US hosted an #NPTRevCon event in a demonstration of nuclear transparency and commitment to nonproliferation. The US is leading on strategic stability, risk reduction, and arms control, and on peaceful uses of nuclear energy - unleashing the Golden Era of US energy dominance.