Mr Sharon hailed the operation as a "success" - although he expressed regret over civilian casualties.
Palestinian militants have vowed to avenge the raid, and in an apparent response on Tuesday a Jewish settler was shot dead and several others wounded near the West Bank town of Hebron.
Monday's raid was carried out by tanks, backed by helicopters and bulldozers, in the southern Gaza Strip town of Khan Younis.
The United States condemned the operation, saying it took place in crowded civilian areas and involved firing on a medical facility.
The European Union, Russia, Egypt and United Nations Secretary General Kofi Annan also voiced strong criticism.
'Massacre'
The BBC's Nick Thorpe in Jerusalem says a list of the 14 people killed published in the Palestinian press includes only one man who is acknowledged as a member of a militant group, the al-Aqsa Brigades.
Despite the international criticism, Mr Sharon defended the raid.
"I think that the operation was a success," he said on Tuesday.
"We have to take into consideration that the Israeli forces are making every effort to contain raids and attacks by terrorist organisations."
He added: "There will be other anti-terrorist operations of this sort in the Gaza Strip."
Mr Sharon insisted many of the dead were armed militants.
"Most of the casualties there were terrorists and are terrorists but still there were some civilians. Therefore I express my sorrow for that," he said.
US State Department spokesman Richard Boucher said Washington was "deeply troubled" by the raid, in which it was reported that a missile was fired into a crowd of civilians.
He urged the Israeli military to "investigate the circumstances surrounding these deaths".
Hamas stronghold
Palestinian officials have described the killings as a "war crime" and called for international protection.
Militant groups have vowed to carry out new suicide attacks inside Israel in response.
On Tuesday suspected Palestinian militants shot dead one Jewish settler and wounded several other in an attack on their car near the West Bank town of Hebron.
Israeli police say the shooting took place at a junction south of the city, apparently from a passing car.
There were also reports of inter-Palestinian violence in Gaza, where Monday's raid was followed by clashes between the Palestinian police and Hamas members triggered by the ambush and killing of a senior security official.
Supporters of the radical Islamic group clashed with police for a second day in Gaza City, reportedly throwing homemade hand grenades at a police headquarters before being dispersed by officers firing into the air, according to an AFP reporter at the scene.
Others Hamas supporters pelted police officers near the funeral of one of four militants killed in gun battles with police on Monday after the death of riot police chief Brigadier General Rajeh Abu Lehya.