BEIJING — China’s president, Xi Jinping, travels to Pakistan on Monday laden with tens of billions of dollars in infrastructure and energy assistance on a scale the United States has never offered in the past decade of a close relationship, a gesture likely to confirm the decline of American influence in that nation.

Mr. Xi, making his first overseas trip this year, and the first by a Chinese leader to Pakistan in nine years, will arrive fortified from the robust reception to the new China-led Asian Infrastructure Investment Bank, and is looking to show that China can make a difference in a friendly, neighboring country troubled by terrorism.

Pakistani officials say that Mr. Xi will be signing accords for $46 billion for the construction of roads, rails and power plants to be built on a commercial basis by Chinese companies over 15 years.

Just as the United States sought to stabilize Pakistan during the war in Afghanistan, so China wants to prevent the spread of militant groups in Pakistan into Xinjiang, the far western region of China with a large Muslim population.