General Mattis, head of US Central Command overseeing the wars in Afghanistan and the Middle East, would meet Pakistan's army chief Ashfaq Kayani for a "regular, scheduled visit", the US embassy in Islamabad said.
"It's not extraordinary... it's a military to military relationship," said embassy spokesman Alberto Rodriguez.
But the visit comes after a US report this week criticised the Pakistani military for failing to forge a clear and sustained path to beat insurgents holed up in the lawless regions bordering Afghanistan.
The semi-annual White House report to Congress, released Tuesday, noted a deterioration of the situation in the Federally Administered Tribal Areas, and said operations were not complemented by plans to "hold" and "build" the areas.
"As such there remains no clear path to defeating the insurgency in Pakistan, despite the unprecedented and sustained deployment of over 147,000 forces," the report said.