Chalara ash dieback has been identified at 82 sites in the UK, including 32 cases in forests and woodlands.
Today's summit is expected to hear the latest update on the situation after hundreds of officials spent the weekend investigating sites for the disease.
The Government has been accused of being too slow to respond to the threat of the disease, but ministers insist they are taking the problem seriously and have brought in a ban on imports of ash trees.
Experts say little can be done to stop the spread of 'Ash dieback' the disease threatening to devastate the UK's ash trees.
One of the UK's biggest tree growers will seek damages from the government after losing thousands of trees to ash dieback disease.
The disease threatening to wipe out the majority of Britain's ash trees may have spread - as experts say an import ban was too slow.