You can’t import a project. You can transfer a sequence. From Premiere Pro, export an XML of the main sequence. Then use SendToX from Intelligent Assistance to convert Premiere’s XML format into FCP’s FCPXML format. Then import the new FCPXML into a Final Cut Pro event.
PS: Some things may or may not translate correctly. Consult the info from Intelligent Assistance for details.
PPS: Actually you may be able to get bins over. Here’s a link to the documentation.
assistedediting.intelligentassistance.com/7toX/help/SendToX%20-%20Help.pdf