Johnston is set to captain Ireland against Kent next Sunday

The all-rounder indicated last week that Ireland's closing World Cup defeat by Sri Lanka might prove to be his last match for his adopted country.

But he said on Sunday that he had "no intention of calling it a day".

Johnston's decision came on the same day that it was announced that Ireland are now 10th in the latest ICC one-day international rankings.

"I'm as fit as I've ever been, and am looking forward to captaining Ireland in the Friends Provident Trophy next week," added Johnston.

The Irish beat Pakistan and tied with Zimbabwe in the group stages of the World Cup in the Caribbean and went on to surprise Bangladesh in the Super 8s.

"We're now ranked in the top 10 sides in the world, and I'd like to see us climb even further up the ladder," said Johnston.

Ireland have made the very most of and learnt from their increased opportunities ICC official Matthew Kennedy

"We've some exciting fixtures lined up over the coming months, including the InterContinental Cup Final with Canada from 22-25 May at Leicester, and a tri-series involving West Indies. There's also talk we'll be taking on India and South Africa."

ICC Global Development Manager Matthew Kennedy described Ireland's move into the top-10 in the international one-day rankings as a "magnificent achievement".

"It shows that they have certainly worked hard, risen to the occasion, and made the very most of and learnt from their increased opportunities," said the ICC official.

"It proves that serious cricketing achievement is possible from within this next tier of nations. Depth and sustainability, and continued opportunity and support, is obviously the key and that is what we will continue to strive for."

Ireland also has ODI status until 2009, a status also enjoyed by the top six Associate Members, the others being Kenya, Scotland, the Netherlands, Canada and Bermuda.

Ireland's promotion to 10th place has knocked Zimbabwe down into 11th.

The Irish begin their Friends Provident campaign with a fixture against Kent at Stormont next Sunday.

The Ireland squad arrive home on Tuesday from the Caribbean.