WELLINGTON, New Zealand (AP) -- The world's biggest iceberg has begun moving nearly three months after it stopped its slow float toward colliding with a huge Antarctic ice tongue, New Zealand officials said Monday.

Known as B15A, the giant iceberg, a remnant of a Ross Ice Shelf fracture in 2000, is now moving slowly northward out of McMurdo Sound, where it had been blocking sea access, Antarctica New Zealand chief executive Lou Sanson said.

He said the iceberg is moving just over a half-mile a day.

Earlier, B15A, which is 1,200 square miles and contains enough water to feed the River Nile for 80 years, was expected to smash into the ice tongue, possibly cracking it apart.

"We know very little about what makes this thing tick. Every time someone has made a prediction about it, they've been proved wrong," Sanson said.