The US military will go ahead with the deployment of a missile defense system in Alaska despite the recent test failure of an interceptor missile, officials said Tuesday.

Pentagon spokesman George Little said the unsuccessful test on Friday of a Ground Based Interceptor (GBI) was no reason to scrap deployment of the weapons in Alaska.

"The test on Friday was not a success and it's being reviewed to see what went wrong," Little said.

"But we maintain that we have a robust defense system in place to defend the United States and her allies from a range of threats.

"There are no plans to change our expansion to 44 Ground Based Interceptors."

The Pentagon announced in March it plans to deploy 14 additional GBI missiles at Fort Greely in Alaska by 2017.

The missiles are in addition to 30 already deployed in Alaska and California, representing a 50 percent increase in GBIs on the continent.

Four tests of GBIs -- costing $70 million each -- since 2010 have all ended in failure.