NEW YORK - Beijing-Washington relationship was the single most important bilateral relationship in the world today, "mutual understanding has never been more important", said Citigroup's CEO to a leading Chinese-American organization here on Thursday.

Vikram S. Pandit, who also participated in the China-US Strategic and Economic Dialogue two days ago, said at the 20th Annual Conference of Committee of 100 that despite the differences, US and China, the world's two leading powers were partners across a range of globally important issues, so they should work more closely together.

"We are the two most important economies in the world, and not just because we are the two largest. Our importance is deeper than that," Pandit said.

He told all the business leaders both from China and the United States at the conference, as a banker, he focused more on the collaborative role that US and China can play in driving world growth.

He said the US, the world's largest consumer market, the biggest innovator and one of the largest manufacturer, had the single greatest impact on global economic aggregates. While the US set the average, China, the world's fastest growing major economy, drove the margin.

"Therefore, it's plain that our countries have two responsibilities, first to manage our own bilateral relationship well and second to jointly manage how the two of us together affect and interact with the wider world."

According to him, both US and Chinese economic growth models faced challenges. The US consumption-driven model resulted in massive public and private debt and huge trade imbalances, while the Chinese investment- and export-driven model was also combined with imbalance between high savings and limited consumption.

The two biggest economies varied from each other, but depended on each other.

"To borrow a Chinese metaphor, over the last few decades, especially before the financial crisis, the US and Chinese economies have been locked in a yin-yang relationship. They are like complementary opposites that together form a whole," he said. "Neither is a well-balanced economy on its own, but together they set the pace for the world."

Pandit said China's new Five-Year Plan was designed to address its problems and US was also trying its best to get the finance in order to trim trade deficit and to create more economic diversification.