SYDNEY, March 1 (Reuters) - Australia has committed A$70 million ($50 million) to fund lethal defensive weapons for Ukraine, including missiles and ammunition, Prime Minister Scott Morrison said on Tuesday.

Australia has shifted from its stance last week when it said it would only fund military technical assistance.

Morrison told reporters on Tuesday the majority of the new weapons funding for Ukraine would be in the lethal category.

"We're talking missiles, we're talking ammunition, we're talking supporting them in their defence of their own homeland in Ukraine and we will be doing that in partnership with NATO."

He said the weapons would be delivered rapidly, but didn't disclose how.

Morrison also urged Australian citizens not travel to join Ukraine's militia in fighting against the Russian military, saying the legal position of foreign civilian combatants was unclear.

"Don't do it," he said.

Australia will commit A$35 million in humanitarian support to international organisations assisting Ukrainians with shelter, food, medical care, water and education, he said.