Secretary of State Hillary Clinton greets embassy staff during a 'meet and greet' event at the US embassy in Kabul, 17 Nov 2009U.S. Secretary of State Hillary Clinton is in Afghanistan to join foreign dignitaries and Afghan leaders Thursday for President Hamid Karzai's inauguration ceremony.

Secretary Clinton says Afghanistan is at a critical moment in its history on the eve of the inauguration of President Hamid Karzai's second term.

Speaking alongside U.S. Ambassador to Kabul Karl Eikenberry, Clinton addressed a few hundred members of the U.S. Embassy staff.

"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 we will have accountability and tangible results that will improve the lives of the people who live throughout this magnificent country," she said.

The Obama administration and other Western leaders have repeatedly urged President Karzai to use his next five-year term to eliminate endemic corruption. Earlier in the week, the Afghan government announced it plans to form a major anti-corruption unit for investigating graft among senior officials.

In Kabul, Clinton reaffirmed U.S. support for Afghanistan, which has suffered from its deadliest year for foreign troops and emerged from a fraud-ridden presidential election.

"We want to be a strong partner with the government and the people of Afghanistan, and I always say both because it is not either or - it has to be both," said the secretary of state.

This is Clinton's fourth visit to Afghanistan and first as U.S. Secretary of State. She arrived in Kabul from Beijing, where she was accompanying U.S. President Barack Obama.

Clinton met with U.S. Embassy leaders, as well as the top military commander for U.S. and NATO troops in Afghanistan, General Stanley McChrystal.

Afghan authorities have deployed additional security throughout the capital before Thursday's inauguration. There is no large public ceremony expected, and it will be held as a private event on the heavily-guarded grounds of the presidential palace.