Sri Lankan helicopter gunships carried out air raids on Wednesday and Thursday to provide cover to ground troops advancing on the southern defences of Kilinochchi, the ministry said.
It is almost impossible to verify casualty claims by either side as independent reporters and aid workers are prevented from travelling to the area.
Sri Lankan government forces have pushed towards LTTE-held territory after Colombo pulled out of a Norwegian-brokered truce with the rebels in January.
Kehelyia Rambukwella, spokesman for Sri Lanka's security and national defence, said that government forces have not entered Kilinochchi, they are around the town while they wait for bad weather to pass.
"We cannot take any chances. We are holding strong and we have moved very significantly towards Kilinochchi. We are quite happy and satisfied with the performance of our forces at the moment," he told Al Jazeera.
Mahinda Rajapakse, the Sri Lankan president, has said he will not accept anything short of the LTTE's total surrender.
The LTTE, which is fighting for a separate state in the north for ethnic minority Tamils, has admitted losing ground to government troops.
However, V Prabhakaran, the leader of the group, vowed last month that his forces would fight on.