Volcanic ash from Chile's Puyehue Cordon Caulle began to drift up New Zealand's South Island on Saturday night. As a result, Qantas and Jetstar airlines have been forced to cancel some flights scheduled for Sunday.

The New Zealand Civil Aviation Authority (CAA) said on Saturday the ash was expected to disrupt national and international flights for the next week as it invaded the country's airspace.

The Australian airline Qantas confirmed it had canceled several of Sunday's flights, including QF45 (Sydney-Christchurch), QF46 ( Christchurch-Sydney), QF121 (Sydney-Queenstown) and QF122 ( Queenstown-Sydney).

Jetstar has canceled a number domestic flights between Christchurch and Auckland, Christchurch and Queenstown, and Auckland and Queenstown on Sunday.

Jetstar has also canceled some trans-Tasman flights, between Christchurch and Sydney, Christchurch and Melbourne, and Queenstown and Melbourne.

So far, Air New Zealand has not canceled or delayed any of its flights despite volcanic ash from Chile.

An Air New Zealand spokeswoman said the company would adjust flight routes and altitudes to ensure aircraft remained clear of any ash.

The Puyehue Cordon Caulle volcano in Chile has been disrupting travel in Argentina, Uruguay and Brazil since it began erupting on June 4.

New Zealand has a Volcanic Ash Advisory System that ensured civil aviation operations could be safely carried out near volcanic ash.

The MetService will track the volcanic ash plumes and provide warnings to the aviation industry here and over the wider area -- roughly from the Equator to the Pole and mid-Tasman to just west of South America.

At this stage the forecast direction of the volcanic ash plumes might initially have an effect on air traffic routes over the South Island, the Christchurch to Australia routes, and the great circle routes between Australia and New Zealand and South America, the CAA said.