The Taliban's advance to the area had caused alarm in Pakistan as well as Washington over the possibility that the nuclear-armed country was destabilizing.
"We assure the nation that armed forces have the capability to ward off any kind of threat," Pakistani military spokesman Maj. Gen. Athar Abbas told a news conference in Rawalpindi, Reuters reported.
Abbas also said soldiers freed 18 of about 70 police and paramilitary troops kidnapped by the militants on Tuesday, reported the Associated Press.
The Pakistani military began its operation Tuesday, using jet fighters and helicopter gunships to fire on militants in the once-peaceful farming region.
In addition, a pilotless U.S. drone fired a missile into Pakistan's South Waziristan, a major sanctuary for al-Qaida and the Taliban, on Wednesday, but there were no immediate reports of casualties, an intelligence official told Reuters.
Pakistani President Asif Ali Zardari is planning to meet in Washington with U.S. President Barack Obama and his Afghan counterpart Hamid Karzai May 6-7 to discuss regional strategy.
The Pakistani government had approved Sharia, or Islamic, courts in Swat Valley in order to end the fighting there, but the Taliban has since spread into other parts of Malakand, including Buner, Lower Dir and Shangla districts, according to Reuters.
Pakistani officials said the Islamic law concession stripped the militants of any justification to retain their arms, and now will use force when necessary against militants who defy the government.
U.S. Democratic lawmakers, meanwhile, are looking to speed up the approval of $400 million in counterinsurgency funding and $1.4 billion in economic assistance for Pakistan as part of a broader $83.4 billion war-spending bill, reported the Wall Street Journal.