Braving bitter cold, 20,000 cheering people in Belgrade waved Chinese and Serbian national flags to welcome Premier Li Keqiang, who was in Serbia in mid-December to witness the completion of the first Chinese-built bridge in Europe.

Spanning the Danube River, the "China Bridge", as locals call it, was designed and built by Chinese companies with preferential loans from China. Li said he expected the bridge to become a calling card for Chinese companies going global.

In photos taken at the event, Li is seen smiling broadly, appearing to radiate sincerity and confidence in his country's capabilities.

It was but one moment in the 34 days Li spent outside China in 2014, sewing up agreements around the world worth billions of dollars.

Li has earned himself the nickname the "Super Salesman of China" for his widely reported efforts in promoting Chinese high-speed railways, 4G communications technology, nuclear power and other infrastructure equipment during his overseas visits. At least $140 billion worth of deals were sealed for Chinese companies and more than 250 agreements were signed during his five official visits last year to 13 countries in Africa, Europe and Asia.

The premier's passion and skill as the nation's salesman are reflected in his articles. His essay, Greetings Across Rivers and Mountains, was published by Baltic News Service, the largest news agency in the Baltic region, on Nov 26, 2013, before his meeting that year with representatives of 16 Central and Eastern European countries.

In it, Li wrote: "China is making rapid progress in the manufacture of transportation equipment, especially high-speed railways. We have a strong capacity and high-quality equipment, and the total length of high-speed railways under operation in China has exceeded 10,000 kilometers. We are fully capable of taking on high-quality transportation infrastructure projects in Central and Eastern European countries.

"China has reached world standards in manufacturing and installing equipment for coal-fired and hydropower stations, including pumped storage power stations. We also have mature technologies and world-class manufacturing capabilities in nuclear, wind and solar energies. Our equipment is inexpensive and of high quality, which makes China an ideal partner for CEE countries."

The classic three-point tactic in salesmanship, experts say, imparts a clear message: "We are good," "Here's how good we are," and "We are good for you."

Li sent a similar message to almost all the countries he visited, each time tailored to meet the needs of the host country and China's ability to fulfill them.

For instance, before a breakfast meeting with Kazakhstan President Nursultan Abishevich Nazarbayev on Dec 15, Li and his team reviewed a national infrastructure upgrade plan released by Nazarbayev a week earlier and noted the country's strong demand for steel, cement, plate glass and thermal power plants.

When Li met Nazarbayev at Beijing Plaza in the central district of Astana, the capital of Kazakhstan, the premier brought to the table a package offer of infrastructure-related equipment and technology. The two soon signed an agreement for future projects worth $18 billion.

Li's approach to business on overseas visits is pragmatic, experts say.

"Premier Li showed a sincere and frank diplomatic style in his foreign visits," said Chen Fengying, director of the World Economy Institute at China's Institute of Contemporary International Relations, a foreign policy think tank.

"I think it's fair to call it smart diplomacy based on our nation's power," Chen added. "Li is always well prepared when he goes into a meeting with his hosts."

Zhang Yuyan, director of the Institute of World Economics and Politics at the Chinese Academy of Social Sciences, said Li's strenuous efforts in promoting Chinese equipment and technology overseas is, in essence, making good use of China's comparative advantages in infrastructure construction in the chain of international labor.

"What Premier Li has been doing in the past year is in accordance with our country's developing momentum," he added.

"We've become one of the major countries now. He demonstrates the confidence of China as a major economy."