Thirteen days since it erupted, the Chilean volcano Puyehue is stable and its activity should diminish further in the coming weeks, the director of the Chile's National Service of Geology and Mining said on Thursday.

"In the next two weeks, volcanic activity should decrease," the head of the service, Enrique Valdivieso, told AFP.

The volcano, which erupted on June 4 spewing a gas column 10 kilometers (six miles) into the air, has caused numerous flight cancellations as far away as Australia and New Zealand.

"We are close to seeing just a bit of lava" on the outside of the volcano, which means the lava is no longer a threat, and also marks the beginning of the end of the eruption process," Valdivieso added.

On Thursday, the column of smoke escaping from the volcano was three kilometers (1.8 miles) high compared with four to five kilometers (2.4 to three miles) the day before and 12 kilometers (seven miles) at the height of its activity.

Meanwhile, Puyehue's ash cloud, which can wreak havoc with aircraft, is about to finish its around-the-world trip following the earth's west to east rotation and arrive back in Chile on Saturday.

Shortly after the first eruption, the cloud passed over Buenos Aires and Montevideo, then Australia and New Zealand, causing severe air traffic disruptions along the way.

By Thursday, however, only a few flights between Australia and New Zealand remained suspended.

Last spring, the eruption of the Eyjafjoll volcano in Iceland caused an estimated 100,000 flight cancellations in Europe over a six-day period.