Aboard the White Star Line's magisterial ship the SS Olympic, Sastri and his team of advisers, Girija Shankar Bajpai (secretary), Geoffrey Corbett (civil adviser) and Colonel K. Wigram (military adviser), left Southampton on 26 October 1921. The Washington Conference was convened by America's President Warren G. Harding to discuss two sets of issues: disarmament and affairs concerning the Pacific. Harding had originally invited a combined delegation of the British Empire, aware that his predecessor, Woodrow Wilson, had been criticized by the republicans for granting the units of the British Empire separate votes at the League. Three dominions – Canada, Australia and New Zealand – had direct interest in Pacific affairs and feared Japan. The dominions were more likely to be supportive of America's plans in the Pacific so Harding wanted them to attend. But as we will note, they also had different interests and positions and insisted that they would sign separately on each of the agreements reached, so that each could withhold their signatures in case of specific disagreements. Lloyd George and Harding had to agree, and since India had a status equal to the dominions, Montagu and Sastri insisted on India's separate representation.

Sastri, who had impressed the Prime Minister at the Imperial Conference, and even more so with his work in Geneva, was the automatic choice for India's representative. India's interest in Pacific affairs may have been marginal except for the issues relating to China, but a conference like Washington was a legitimacyenshrining platform. India's claim to dominion status would be bolstered by its equal representation at what promised to be a defining international conference.

The five-day journey to New York was spent in relative luxury, Sastri's cabin was ‘a commodious little house’. But his mind was uneasy. On the very day Sastri took the ship westwards, the Prince of Wales had travelled eastwards to India as part of his empire-wide tour to show the king's appreciation of his subjects’ contribution to the war. Sastri had strongly advised against the prince's visit. Gandhi had announced a boycott. The visit, Sastri reasoned, would provide new momentum to the otherwise declining non-cooperation movement.