Secretary of State Marco Rubio is arguing that the presence of two Hong Kong companies and other Chinese firms violates a treaty Panama has with the U.S.

Secretary of State Marco Rubio told Panama officials that Chinese influence over the Panama Canal must be curbed or the U.S. will take retaliatory actions, the State Department said Sunday. Why it matters: Rubio's warning to Panama President José Raúl Mulino and Foreign Minister Javier Martínez-Acha is another pressure point on the country since President Trump said he intended to regain control of the Panama Canal.

President Trump has made a “preliminary determination” that Chinese influence violates a treaty that assures the canal's neutrality, Rubio said.