In February of the following year he traveled to Geneva in order to collaborate with ambassador Afrânio de Melo Franco in the negotiation process for Brazil's admission as a permanent member of the council of the League of Nations.

The Brazilian candidacy had been presented shortly after the signing, in December 1925, of the Locarno Treaties, in which the great powers decided to expand that council in order to allow Germany's entry.

[6][7] He obtained from King Manuel II of Portugal an autographed gift of the volumes of the large, exquisitely illustrated catalogue, from the monarch's private library.

He ended his assignment in London on December 26, 1939,[8][9] shortly after the start of World War II, retiring from diplomatic service.

In June 1933, he represented Brazil at the London Monetary Conference, which attempted to establish cooperation measures between nations for the recovery of the world economy, shaken by the 1929 crisis.

The conference ended in complete failure, serving only, as Régis de Oliveira in a report, to clarify the differences between the main Western powers.