Scientists at Sandia National Laboratories claim to have successfully tested an upgraded version of the B61-12 nuclear bomb.

The US has been working on the B61-12 for several years, and government officials say the latest tests are vital to refurbishing efforts.

An F-16 from Nellis Air Force Base in March successfully dropped a zero-yield version of the bomb over the Nevada desert. It left a "neat hole" and crews were able to dig it out of the dirt for further study.

Sandia Stockpile Resource Center Director Anna Schauer said, "It's great to see things all come together: the weapon design, the test preparation, the aircraft, the range and the people who made it happen."

Scientists will spend the next several months analyzing data gathered from the test flight.

Officials say the US is planning more test flights over the next three years, and the B61-12's first production unit is scheduled to be completed in 2020.

The current B61-12 consolidates and replaces four older versions in the nation's nuclear arsenal.