You can protect your invention in other country by filing a Patent Cooperation Treaty (PCT) application or by filing directly in specific countries. You can also claim the filing date of a provisional patent application or a utility patent application for PCT applications and foreign applications filed within a year of the original application.
A PCT application can also delay many of the costs of filing and examining a patent in other countries. The PCT application does not need to be nationalized for examination in specific countries until 30 months after the filing date of the initial priority applicaitin. Thus you can significantly delay the costs.
You can file a PCT application as the initial (priority) patent application for your invention. This is often done when early international protection is desired.
PCT applications can also be filed that claim priority to a utility patent application or a provisional patent application.