First, communicate the issue to your peer openly. Try to base on facts and avoid just opinions. Direct communication shouldn't a problem these days as jmort points (+1). Chances are you peer is just unaware what he's expected to do and with some guidance not only would he help you but also would be grateful for help.
Second, be prepared that not taking responsibility for the project may be just a symptom of some deeper problem which can be totally out of your control, like you peer may be totally overwhelmed with other, more important, projects or may be just incompetent. In this situation you may either try to investigate the root cause of the issue or try to escalate your problem. I'd start with letting know your peer's supervisors as it's usually pretty successful method.
Third, there is some kind of agreement between two project teams. You don't mention any other company so I assume both project teams are parts of the same organization thus I don't expect any formal agreements but then there probably are some informal arrangements that guys over there would deliver leak-free kettles so you can build kettle of the future. Otherwise you wouldn't depend on them, would you? Now, if you can't solve the issue by yourself you should make aware of the problem people who made these arrangements in the organization. This starts to be large caliber gun so you may want to wait with that until you have no other options.
Fourth, independently of all others you should treat the situation as your project's risk and make it visible for everyone interested. It would help you to share the issue with people involved in your project, including your supervisors and also it should make it easier to get some help with your efforts to solve the problem, especially that most likely you'll need to engage other people in organization anyway.