US President Donald Trump congratulated Saudi Arabia Tuesday for its decision to join the rest of the world in allowing women to drive, calling it a "positive step" for the ultra-conservative kingdom.

"President Donald J. Trump commends the Kingdom of Saudi Arabia´s decision today to affirm the right of women to drive in the kingdom," a White House statement read.

"This is a positive step toward promoting the rights and opportunities of women in Saudi Arabia."

Saudi king issues decree allowing women to drive: state media

The royal decree orders formation of a ministerial body to implement order by June 2018

Earlier, State Department spokeswoman Heather Nauert hailed the "very positive sign."

"We´re just happy today," she added.

Earlier, Saudi officials had announced that it would allow women to drive from next June, a victory for a long campaign by women´s rights activists.

"We will continue to support Saudi Arabia in its efforts to strengthen Saudi society and the economy through reforms like this," the White House said.