KABUL, Afghanistan - U.S. Secretary of State Hillary Rodham Clinton stressed Wednesday that the United States will keep pressing the Afghan government to crack down on rampant corruption, saying the American military cannot defeat militancy without the help of a strong partner.

Clinton arrived in the Afghan capital on the eve of President Hamid Karzai's inauguration, during which he will make a speech that many hope will outline concrete commitments to reform, helping the country move past a fraud-tainted election that undermined trust in the government.

"We are concerned about corruption, and we obviously think it has an impact on the quality and capacity of governing," Clinton told reporters as she flew from Beijing to Kabul, her first trip to the country as secretary of state. "So we're going to be persistent, asking for the kinds of outcomes that we think reflect that they are serious about this."

Karzai, who won the election by default after his main rival pulled out of a runoff saying it was impossible for the vote to be fair, has often bristled at the intense international pressure he has come under over corruption in his government. Although he acknowledges his administration faces problems, he has stressed that graft is also pervasive in the international contracting process in Afghanistan and that foreign aid is being wasted before it ever gets to the Afghan people.

The Karzai government unveiled an anti-corruption and major crimes unit last week to signal that he was determined to tackle the issue as international pressure ramps up, including a warning that U.S. military and financial support will be tied to reform.

In remarks to employees at the heavily secured U.S. Embassy compound in the capital shortly after her arrival, Clinton lauded the U.S. military, then went to meet with the top U.S. military commander in Afghanistan, Gen. Stanley McChrystal, who has advocated sending tens of thousands of additional U.S. troops.

"Nobody knows better than our military commanders that troops alone cannot meet our goals of defeating al-Qaida, of helping the Afghans get the capacity to defend themselves and provide governance that will result in positive changes for the people of this country," she said.

"The military has performed brilliantly, time and time again, in confronting terrorism and protecting civilians and training security forces and defending borders, but this has got to be a common joint strategy that we look at from the beginning - not as an afterthought," said Clinton, who later dined with Karzai at the presidential palace on Wednesday evening.

Clinton's trip to Kabul comes just days after U.S. Ambassador to Afghanistan Karl Eikenberry, in leaked memos, questioned the wisdom of adding American troops at a time when the Afghan political situation is unstable and uncertain.

Clinton, who has visited Afghanistan four times before, arrived from Beijing, where she was accompanying President Barack Obama on his trip to Asia. She is one of more than 40 dignitaries from the U.S., Europe and other countries scheduled to attend Thursday's ceremony.

"There is now a clear window of opportunity for President Karzai and his government to make a new compact with the people of Afghanistan to demonstrate clearly that they're going to have accountability and tangible results that will improve the lives of the people who live throughout this magnificent country," Clinton said.