One of the main ice shelves in Antarctica could break off at any moment, setting an iceberg the size of Delaware drifting towards South America, scientists have warned after new analysis.

A deep crack in the Larsen C ice shelf has extended to about 200 km long, "leaving just 5 km between the end of the fissure and the ocean," said the European Space Agency on Wednesday.

As its area is almost 5,200 square kilometers, the iceberg "could pose a hazard for ships in Drake Passage", said Anna Hogg, a scientist from the University of Leeds.

The European Space Agency has been using satellites to observe icebergs for many years. / ESA Website

In fact, scientists have been monitoring the potential hazard for two years, since they observed the crack in Larsen C growing rapidly.

It was 178 kilometers long in January of this year but has grown rapidly since then. In June, the crack made the Larsen C ice shelf and the enormous iceberg "connected by just 8 miles [12.8 kilometers] of ice", according to Reuters.

At present, the remaining ice has "strained near to its breaking point", said Adrian Luckman, a scientist from Swansea University in Wales.