US President Barack Obama (R) welcomes Chinese President Xi Jinping in the Oval Office of the White House in Washington September 25, 2015. [Photo/Agency]

There is no doubt that President Xi Jinping and President Barack Obama, or any top Chinese and US leaders, should hold summit meetings more often.

The reason is quite simple. Such summits have the potential to change the dynamic of China-US relations for the better, as has been proved by the three summits between Xi and Obama.

The two leaders met in June 2013 in the California desert retreat of Sunnylands, in November 2014 in Yingtai, an imperial palace in Beijing's Zhongnanhai, the headquarter of China's central government, and last week in Blair House, across the street from the White House.

The shirt-sleeves summit in Sunnylands, which was held a few months after Xi became Chinese president and less than five months after Obama assumed his second term, turned out to be a good opportunity for the two leaders to get to know each other better and build a closer personal relationship. With a private dinner and formal group meetings, the two leaders met for more than eight hours, unlike the 30-minute chats they usually had on the sidelines of multilateral events.

Ben Rhodes, Obama's deputy national security advisor for strategic communication, recently cited Obama as saying the private dinners at the summits have been the most constructive part, because he and Xi didn't have to go through the long list of items on formal agendas and state their country's stance, as happens in formal meetings. Instead they could conduct in-depth talks about where they wanted to take their country and offer a vision of how the US and China might work together.

Rhodes attributed the historic climate agreement announced in Beijing last November during Obama's trip to Beijing as an outcome of the two leaders' informal conversations in the relaxed setting of Sunnylands.