President Trump said the agreement would partly walk back some of the steep tariffs he threatened on the country last week. Indonesia’s president called Mr. Trump a “tough negotiator.”

US solar manufacturers said they have filed new trade petitions against India, Indonesia and Laos alleging illegal practices by largely Chinese-owned companies operating in those countries.

Indonesia’s recent agreements with the Western superpower and the European bloc could set the path for other nations seeking similar arrangements. But experts warn against potential pitfalls and sacrificing domestic interests.