Angarietis was CPL representative and contact person at the Comintern. He was a delegate at the 3–7th Congresses of the Comintern. During the 5–7th Congresses he was elected to the International Control Commission, of which he was secretary in 1926–1935. He was also a delegate to the 6th, 8th, 10th, 12–17th Congresses of the Russian Communist Party.