US Defense Secretary Donald Rumsfeld has held talks in Pakistan with President Musharraf on the operation against militants in South Waziristan.
Mr Rumsfeld arrived in Pakistan for a brief visit as part of his Asian tour. The US consulate in Karachi was closed during his stay due to security fears.
The US is happy with Pakistan’s efforts to clear areas close to Afghanistan of militants, a BBC correspondent says.
The US reaffirmed offers of military aid, Pakistani officials said.
“He said the US would be stepping up support to meet Pakistan’s legitimate defence needs,” they added in a statement.
Officials said these included the proposed sale of F16 fighter aircraft to Pakistan as well as Islamabad’s request for the purchase of other US military hardware.
Mr Rumsfeld – who has now left Pakistan – acknowledged the heavy casualties Pakistani troops have suffered since the start of the South Waziristan operation early last year.
The BBC’s Zaffar Abbas in Islamabad says that Mr Rumsfeld’s visit served as a reminder of the American desire to maintain a close strategic relationship with Pakistan.
Soon after his arrival, he went into extensive talks with General Pervez Musharraf, who is regarded by President Bush as one of America’s most trusted allies in the region.
Officials said the ongoing security operation against al-Qaeda and its local support base in the tribal region of south Waziristan was the main topic of discussion.
Our correspondent says that the US is quite pleased with the way the Pakistani security forces have cleared large parts of the border region from Arab, Uzbek and other foreign and local militants.
Washington has also acknowledged the heavy casualties Pakistani troops have suffered since the start of the operation early last year.
Mr Rumsfeld praised Pakistan’s important role in promoting regional peace and stability and its critical cooperation in the global war on terrorism
Pakistan Foreign Ministry statement
But Pakistani officials say with a new wave of armed attacks by the Taleban in neighbouring Afghanistan, the United States wants Islamabad to spread its security operation through the entire border region.
It is not clear if in their meeting in Islamabad the two sides agreed on expanding the security operation to other border areas to deny Taleban fighters a safe refuge inside Pakistani territory.
Earlier on Wednesday, Mr Rumsfeld met the Afghan President Hamid Karzai in Kabul.
After their talks Mr Karzai said his country wanted a long-term security relationship with the United States.