Official policy would suggest that they are allies but in truth the relationship is more complex than that.
Militarily they are neutral; China has opposed or at least failed to support most major US foreign policy activities including the invasion of Iraq and the current action in Afghanistan.
Similarly the US has some major reservations on the Chinese approach to human rights and has openly commented on Chinese policy on sovereignty issues in Tibet and Taiwan.
However, both sides are aware of the economic value that a mutually peaceful, or at least mutually tolerant relationship provides.
The worlds two largest economies need an active and beneficial trade process to ensure that both countries prosper financially, the US is China's largest export target market and China presents huge opportunities for US companies in terms of growth, outsourced manufacturing and also in terms of raw material and minerals.
So the simply answer would be that they are economic allies but neutral militarily.
They have always been allies...
allies war of 1812
Major allies were Great Britain and France. Major enemies were the Soviet Union and the People's Republic of China.
The US will need to get allies, first.
Germany, Italy, Japan
NVA/VC vs US/allies
The Allies were The US,China,Great Britain,France, and the Soviet Union.
Laos was neutral. Nationalist China (Taiwan) was an ally but did NOT send men to Vietnam. If Taiwan had gotten involved in Vietnam, Red China might have gotten involved too. Red China and Nationalist China were bitter enemies in the 1960's.
China, Timbuktoo, India, Vietnam. This is a little yierd that China and India are the two enemies. It is just like Thailand, and little brother of the US as well as a flatterer behind China's back. The answer above me is correct. Germany and France are one of Russia's allies. Don't get me wrong. Some countries in Europe are Russia's allies. China and Vietnam are their friends. The United States, I don't think so, but they are most likely not enemies either. and russia does love America
Italy, Germany, and Japan were the Axis, enemies, of the Allies in WW2. The Allies were U.S., Russia, France, Great Britain, and China, a.k.a. the Big Five of the United Nations.
The allies of the US were Great Britain, free France, Russia and non-communist China. None of the members of the British Commonwealth were enemies . None of the nations occupied by the Germans and Italians were enemies. Switzerland and the Scandinavian countries were not enemies. None of the South American countries were enemies although Argentina was sympathetic to the Germans. None of the French and Dutch possessions were enemies.
China, Russia, England and France were the four major allies