China's President Xi Jinping is due in Pakistan, where he is expected to announce $46bn (£30.7bn) of investment.
The focus of the spending is on building a China-Pakistan Economic Corridor (CPEC), running from Gwadar in Pakistan's Balochistan province to China's western Xinjiang region.
Pakistan hopes the investment will boost its struggling economy and help end chronic power shortages.
Leaders are also expected to discuss co-operation on security.
President Xi will spend two days in Pakistan holding talks with his counterpart Mamnoon Hussain, Prime Minister Nawaz Sharif and other ministers. He will address parliament on Tuesday.
Deals worth some $28bn are ready to be signed during the visit, with the rest to follow. The sum significantly outweighs American investment in Pakistan.
The CPEC network of roads, railways and energy developments will eventually stretch some 3,000km (1,865 miles).
It will give China direct access to the Indian Ocean and beyond, marking a major advance in its plans to boost its economic influence in central and south Asia.
Pakistan, meanwhile, hopes the investment will enable it to transform itself into a regional economic hub.
Ahsan Iqbal, the Pakistani minister overseeing the plan, told the AFP news agency that these were "very substantial and tangible projects which will have a significant transformative effect on Pakistan's economy".
In quotes carried by China's Xinhua state news agency, Mr Xi said China and Pakistan needed to "deepen practical co-operation and work together for common development".
"We will build the China-Pakistan community of common destiny and set a fine example for such efforts by China and its neighbouring countries."
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