BEIJING, March 31 -- The Asia Infrastructure Investment Bank (AIIB) is designed to bridge a gap, so is Jacob Lew's China trip.

The United States is slightly yet encouragingly changing its mind over the AIIB, as the visiting U.S. treasury secretary told China on Monday that America is looking forward to cooperating with the bank through mechanisms accepted by the two countries.

Just one day before the March 31 deadline for the application of AIIB's founding membership, the United States, together with its staunch ally Japan, still show no sign of joining the bank.

By trying to forge an anti-AIIB front within its allies, Uncle Sam has, intentionally or involuntarily, turned the AIIB into a test of diplomatic strength.

Ironically, the front was broken by its own allies. The AIIB has gained wide support not only in Asia but also in Europe, which clearly told Washington that it had picked up a wrong fight.

In fact, the China-proposed bank is nothing short of a complement to the U.S.-dominated world lending system, including the International Monetary Fund and the Asia Development Bank(ADB), which have been proved incompetent in face of Asia's growing appetite for investment in infrastructure.

According to estimates of the ADB in 2009, the investment demand in Asia alone could reach 8 trillion U.S. dollars between 2010 and2020, of which 68 percent would be for new capacity.

But the ADB controlled by America and Japan could only provide new loans of around 13 billion dollars annually to the region, leaving a gap of over 700 billion dollars every year.

Besides, the loathness or incompetence of the United States to reform the international lending system to accommodate the emerging market countries has greatly damaged its credibility and efficiency.

To bridge those gaps and provide a complement to the flawy system, China proposed the AIIB, which serves no one's hegemony appetite and will bring win-win results to all.

Unfortunately, with deeply rooted zero-sum mentality, some hard-nosed politicians in Washington have misread, maybe deliberately, China's good will, claimed it another sign of "China threat," and turned the AIIB into an America's diplomatic fiasco.

Anyway, it is a welcoming sign that America has begun to change its attitude toward the AIIB, whether it is to save grace or to show good faith.

This is a good start, but not enough. To diminish those gaps mentioned above, it is desired that Uncle Sam join hands with China and other countries to make a better global lending system and a better world.