You can write to urge the following countries to sign the Treaty, via their Embassy to the US, their Head of State, or a local ICAN partner:

Russian Federation

ICAN Partner: Russian Physicians for the Prevention of Nuclear War (RPPNW)
14 Solyanka stz
109544 Moscow,
RUSSIA
E-Mail: Dr. Vladimir Garkavenko

China

ICAN Partner: IPPNW China
Chinese Medical Association
42 Dongsi Xidajie, Beijing 100710
CHINA
Email: Dr. Kaibao Li

United Kingdom

ICAN Partner: Campaign for Nuclear Disarmament
162 Holloway Road, London N7 8DQ
UNITED KINGDOM
E-mail: Kate Hudson

France

ICAN Partner: Abolition Des Armes Nucleaires
21 ter Rue Voltaire,
75011 Paris
FRANCE
E-mail: Dominique Lalanne

India

ICAN Partner: Indian Doctors for Peace and Development (IDPD)
139-E, Kitchlu Nagar,
Ludhiana – 141001
INDIA
E-mail: Dr. Arun Mitra

Pakistan

ICAN Partner: Pakistan Doctors for Peace and Development
P.M.A. House
Garden Road
Karachi, 74400,
PAKISTAN

Israel

ICAN Partner: Physicians for Peace and the Preservation of the Environment
Kfar Yedidia, Haparsa Rd, P.O. Box 19
42940,
ISRAEL
E-mail: Dr. Ra’anan Friedmann

North Korea (Democratic People’s Republic of Korea)

ICAN Partner: Korean Anti-War Peace Physicians
7-30 Ryonhwa-dong,
Central District, Pyongyang
DEMOCRATIC PEOPLES REPUBLIC OF KOREA
Phone: +850.2.18111 / 18222 / 18333 X 8084
Fax: +850.2.3814644
E-mail: Dr. Choe Chang Sik