It means British balloonist Brian Jones and his Swiss co-pilot Bertrand Piccard have broken the ballooning distance record since setting off from the Swiss Alps on 1 March.

They are now one step closer to becoming the first to circle the globe in a balloon.

"After six days and 16 hours over the Pacific the Breitling Orbiter III has reached the Mexican coast at 0145 GMT," spokeswoman Patricia Fournier said from team headquarters in Geneva.

She said the balloon entered Mexican airspace near Colima, some 310 miles west of Mexico City.

They will now head across the Atlantic to North Africa.

Earlier Bertrand Piccard told a Swiss radio station from the Breitling Orbiter 3 the team was optimistic but added: "We can't claim victory too soon. There could still be problems."

Brian Jones: Dreams of landing near Giza

The Breitling team reached Mexico after six days of a mainly problem-free flight over the Pacific Ocean, the most treacherous part of the journey.

The balloonists, both nursing colds at an altitude of 35,000 feet, aim to pass south of Cuba on Thursday.

The two hope to cross the "finishing line" above Mauritania on Saturday afternoon, although their final landing place has not yet been decided.

"The problem with landing in Mauritania or the Western Sahara is the infrastructure is not there for an around-the-world balloon landing," said flight director Alan Noble.

"We are considering keeping it flying an extra day and possibly putting down in Egypt, but there is no decision yet," he said.

Pilots can fly over storms

Luc Trullemans, team meteorologist from Belgium's Royal Meteorology Institute, said a "stable" jet stream awaited the pair over the Atlantic.

"We have to be on the lookout for storms, over the Gulf of Mexico for example. But the pilots are flying so high that they can pass above storms," Mr Trullemans said.

Alan Noble: Balloonists aim to land in North Africa

"Brian Jones has always said that his dream is to land near the pyramid in Giza," he added.

Although the control centre are nervous of "jinxing" the flight by appearing too confident, the two pilots seem very relaxed.

On Tuesday, Mr Piccard painted a picture of the domesticity he has come to share with Mr Jones, 51, from Erlestoke, Wiltshire.

After 15 days in the air, the Swiss pilot said: "This morning, when I woke up and Brian was ready to sleep, he made me a cup of tea while I was preparing his bed.

"We realised how our relationship was deep and friendly."