Although the two leaders had a strong relationship, by 1960 US officials were becoming concerned by what they viewed as Canadian procrastination on vital issues, such as whether Canada should join the Organization of American States (OAS). Talks on these issues in June 1960 produced little in results. Diefenbaker hoped that US Vice President Richard Nixon would win the 1960 US presidential election, but when Nixon's Democratic rival, Senator John F. Kennedy won the race, he sent Senator Kennedy a note of congratulations. Kennedy did not respond until Canadian officials asked what had become of Diefenbaker's note, two weeks later. Diefenbaker, for whom such correspondence was very meaningful, was annoyed at the President-elect's slowness to respond. In January 1961, Diefenbaker visited Washington to sign the Columbia River Treaty. However, with only days remaining in the Eisenhower administration, little else could be accomplished.