Compared to Beijing's consistency, messages from politicians in Washington about US-China relations tend to be mixed and confusing.

A simple glance at three news stories in the last week demonstrates this fact once again.

On May 25, the US House of Representatives broadened the type of Chinese entities barred from receiving Pentagon contracts. One day later, Secretary of Commerce Gary Locke criticized China's market access and its slow revaluation of the yuan.

Then on Tuesday, Kurt Campbell, the top US diplomat for East Asia, downplayed Washington's differences with Beijing and said the United States wants to deepen cooperation with China in Southeast Asia this year.

As such, it can be difficult to fathom whether Washington really wants to cooperate with Beijing or treat it as a rival.

In fact, the world is no stranger to the juxtaposition of polarized rhetoric from the "China bashers" and "Panda huggers" in the US on a wide range of hot issues between the two countries. It is also familiar with the US' penchant for playing the China card in its domestic politics.

Although China-US ties have maintained good momentum in general since the beginning of the year, the blatant finger pointing and discrimination against Chinese companies could run the risk of chilling bilateral ties once again.

Both countries should cherish this desirable momentum and avoid missteps that could lead to a cooling in relations again.

The latest move by the US House of Representatives constitutes a disservice to bilateral ties and it speaks volumes about the anti-China undercurrents in the US political apparatus.

Under the House amendment, all entities owned by or affiliated with the Chinese government are prohibited from providing defense articles to the US and the US secretary of defense must report to Congress 15 days before any planned waiver of the ban.

Such discrimination against China, under the excuse of defending the US' national interests and national security, disproves the self-declared openness of the US market and reveals the psyche of those in the US who project China's development as a threat rather than an opportunity for greater cooperation.

Given their status as the world's two largest economies and their trade interdependency, reciprocal cooperation in all fields will benefit not only the two economies but also the global economy.

Resorting to discriminative acts or double standards in trade not only goes against the trends of the times but also hurts the healthy growth of bilateral ties.