ISLAMABAD- Chinese President Xi Jinping today arrived in Pakistan to launch $46 billion in projects linking the old allies, a figure that far exceeds U.S. spending in Pakistan and underscores China's economic ambitions in Asia and beyond.

The infrastructure and energy projects are aimed at establishing a Pakistan-China Economic Corridor between Pakistan's southern Gwadar port on the Arabian Sea and China's western Xinjiang region.

The plan is part of China's aim to forge "Silk Road" land and sea ties to markets in the Middle East and Europe and reflected a shift of economic power in the region to China, said Mushahid Hussain Sayed, chairman of the Pakistani parliament's defence committee.

"Pakistan, for China, is now of pivotal importance. This has to succeed and be seen to succeed," he said.

The corridor, a network of roads, railways and pipelines, will run through Pakistan's poor Baluchistan province, long plagued by a separatist insurgency which the army has vowed to crush.

The security of Chinese workers will be a prime concern for Xi. In his talks with Prime Minister Nawaz Sharif and military leaders, Xi is likely to raise China's fears that Muslim separatists from Xinjiang are teaming up with Pakistani militants.

Xi has linked economic cooperation with security.

"Our cooperation in the security and economic fields reinforce each other, and they must be advanced simultaneously," he said in a statement to media on the eve of his two-day visit.

Xi is also likely to call for greater efforts to bring peace to Afghanistan, where Pakistan is keen to restrict the influence of is rival India.