The most senior U.S. diplomat for Asia has met the Philippine foreign affairs secretary just days after Philippine President Rodrigo Duterte, during a visit to China, said he intended to sever ties with the U.S.

Daniel Russel said he told Perfecto Yasay Monday that Duterte's "succession of controversial statements and comments and a real climate of uncertainty about the Philippines' intentions has created consternation in a number of countries, not only in mine."

On Saturday, President Duterte backpedaled a bit on his comments in Beijing, saying he is not actually cutting ties with the U.S. because "It's in the best interest of my country that we maintain that relationship." But he said Manila will make its own foreign policy decisions independent of Washington.

Russel said Washington welcomes the relaxation of tensions between Manila and Beijing under Duterte, but the rapprochement should not come at the expense of ties between the U.S. and the Philippines.

Russel said he also shared concerns the U.S. has with Manila's anti-drug campaign that has killed more than 3,000 people in three months.

After the Philippines, Russel visits Thailand where he will convey his condolences on the death of King Bhumibol Adulyadej and meet with Thai officials to discuss bilateral relations and regional issues.

U.S. Assistant Secretary of State for East Asian and Pacific Affairs Russel will then head to Cambodia to meet with government and opposition party officials and civil society organizations.