Chinese President Hu Jintao has landed at Andrews Air Force Base for a state visit in the United States. He was welcomed upon his arrival by Vice President Joe Biden and a military color guard.
Hu comes to the US amid tensions between the two world powers over economic, trade and security issues.
President Barack Obama has arranged for Hu to be greeted with full pomp, complete with a state dinner on Wednesday.
That is a change from Hu's previous visit in 2006.
China is an emerging world power. It has strategic national security importance for the United States.
Its trade and currency policies have frustrated the US business community, which sees China as huge market for American exports.