I am from Jamaica and I have a US visitor's visa. I recently arrived in Canada and am awaiting my first permanent resident card. I need to travel to the US.
Can I travel to the US on my visitor's visa issued in my Jamaican passport?
Welcome to Canada!
Yes. I have been travelling to the USA for almost eight years as a Canadian Permanent Resident on my Hungarian passport and the B1/B2 visa in it -- there's nothing else to travel with, the USA does not recognize or care much about your PR card. The only time when it matters is in three years when you can ask for a NEXUS card to make border crossings easy.
Careful, however, about leaving Canada without your PR card! You need it to enter Canada again via air. While I was waiting, I took the bus across, had no issues, this is not fresh information though, it was in 2008 fall but as far as I am aware, this did not change. Read http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=064&top=10 although this mentions bus, I had absolutely no problems four times boarding Quickshuttle and crossing at Blaine into Vancouver.