China and Pakistan refer to themselves as "all-weather friends", united in their rivalry against mutual neighbour India and entwined in a web of military, political and economic links.
President Xi told PM Khan that he valued both countries' relations, and reaffirmed their "all-weather" friendship.
Xi assured Khan that China considers its relations with Pakistan a diplomatic priority.
Fawad Chaudhry said that PM Imran's meeting with the Chinese president was successful.
China is preparing to roll out the red carpet for Mr. Khan, who is set to arrive in Beijing on Friday, and would be formally welcomed at the Great Hall of the People on Saturday.
"Pakistan looks forward to strengthening its cooperation with the AIIB", he said, informing the AIIB president that his government has prioritized economic revival and structural reforms.
The country's foreign exchange reserves have fallen to a near five-year low of US$7.8 billion, the State Bank of Pakistan said on Thursday, while the net foreign reserves held by commercial banks have also dropped, to US$6.4 billion. He said we desire to learn from the experiences and successes of China in different sectors.
Pakistan has taken out billions of dollars in loans from China in recent years for infrastructure projects, the terms of which remain largely undisclosed.
USA secretary of state Mike Pompeo has expressed opposition to using International Monetary Fund money to repay Chinese loans.
Khan is being accompanied on his visit by several senior government officials, including Foreign Minister Shah Mehmood Qureshi, Finance Minister Asad Umar, commerce and trade adviser Abdul Razzak Dawood and Railways Minister Sheikh Rasheed.
It is also seeking fresh loans from Saudi Arabia and China, discussion of which is expected to dominate Khan's visit.
While Commerce Minister Dawood told the Financial Times that some of the CPEC agreements were unfair to Pakistani companies and should be put on hold for a year, Railways Minister Rasheed said that Pakistan wants to cut the size of the Dollars 8 billion Karachi-Peshawar rail line, the biggest project of the CPEC, by USD 2 billion.
The so-called "CPEC" involves a host of projects with an aim to connect China's Xinjiang province with Balochistan's Gwadar port.
"Basically, aside from the contracts that have been agreed and the projects that are moving ahead on the ground, which is the $19 billion worth, everything else is up for grabs as far as they (China) are concerned", Small said.
Khan's visit to China will provide an "opportunity" for the two countries to open a "new chapter" of bilateral relations "under the new circumstances", Chinese Foreign Ministry spokesman Lu Kang said on Monday.
The Pakistan prime minister's office said later that Xi had accepted an invitation to visit to the country.