The United States is China's "committed partner and friend," Secretary of State Hillary Clinton said Thursday as she sent greetings to Beijing ahead of its National Day celebrations.

"Together, our two countries are seizing this moment in history and developing the positive, cooperative, and comprehensive relationship envisioned by our presidents," Clinton said in a statement.

"The United States is committed to the success of China, because a thriving China is good for America and a thriving America is good for China," she said ahead of October 1, when Beijing marks the founding of the People's Republic.

Clinton added that by working together, the two countries can "find solutions to our most pressing global challenges."

"On this 62nd anniversary of the founding of the People's Republic of China... know that the United States stands with you as a committed partner and friend."

The sometimes tense relationship between the world's two largest economies took its latest hit when Washington announced it would upgrade Taiwan's F-16 fighter jets, prompting Beijing to warn military ties would be affected.

Chinese President Hu Jintao made a state visit to the United States in January, following one to Beijing by US President Barack Obama in November 2009. US Vice President Joe Biden visited China in August.

China is the largest foreign holder of US debt, and in recent months had cautioned Washington to get its financial house in order, but Premier Wen Jiabao expressed confidence in the US economy during Biden's visit.