General David Petraeus has arrived in Pakistan on his first international trip as head of US Central Command, reported Aljazeera.
Petraeus, who is responsible for conducting the the wars in Afghanistan and Iraq, will meet military and government officials on Monday, with relations strained over cross-border raids by US forces.
In a sign of the challenge facing Pakistani and US forces along the border with Afghanistan, just hours before his visit, eight Pakistani paramilitary soldiers were killed in a blast in South Waziristan.
The suicide attack at a Frontier Corps checkpoint in Zalai came after two targets in Pakistan were hit by suspected US missiles on Friday.
At least 12 suspected fighters were killed by two missiles fired by a suspected US drone near Wana.
That raid followed an attack in neighbouring North Waziristan, where two missiles killed 20 suspected Arab fighters, including al-Qaeda's propaganda chief, security officials said.
US forces or intelligence agents are suspected of carrying out at least 17 missile attacks in Pakistan since August. Pakistan has condemned them as violations of the country's sovereignty, but the raids have continued.
Petraeus's trip signals Pakistan's crucial role in Washington's so-called "war on terror", particularly in the escalating conflict in neighbouring Afghanistan.
Pakistan has deployed security forces throughout the northwest of the country in an attempt to combat fighters sympathetic to the Taliban and al-Qaeda, which Washington says are crossing the porous border to attack US and Nato-led troops.
Petraeus is accompanied by Richard Boucher, the US assistant secretary of state, on the visit.
"They are here for previously scheduled meetings with government and military officials," Lou Fintor, US embassy spokesman, said.
The defence ministry said the two Americans would meet Chaudhry Ahmed Mukhta, the defence minister, on Monday. While Petraeus would also hold talks with General Ashfaq Kayani, Pakistan's army chief, a military spokesman said.
Another topic that could come up during Petraeus' visit is negotiations with the Taliban. Pakistani and Afghan leaders recently vowed to seek talks with elements of the movement in an attempt to stem the surging violence.
Petraeus, previously the senior US commander in Baghdad, has indicated support for efforts to reach out to members of the Taliban considered moderate enough to co-operate with the Afghan government.