"It is our collective objective to strengthen strategic ties between our two countries," he told a joint session of Pakistan's parliament before leaving to return to China Sunday afternoon.
Boosting trade and investment with Pakistan was the focus of the first visit by a Chinese premier in five years to the country, which is battling a Taliban insurgency and is at the forefront of the US-led war on Al-Qaeda.
Business leaders and cabinet ministers formalised around 35 billion dollars' worth of trade deals during the visit, signing a raft of agreements designed to prop up Pakistan's ailing economy and ease its crippling energy crisis.
Wen, who arrived in Pakistan straight from a visit to arch-rival India, Sunday predicted "sustained growth of our economic and trade ties" as the 60th anniversary of diplomatic relations between Beijing and Islamabad approached.
He welcomed Pakistani efforts to increase exports to China and said the two countries would explore the possibility of a currency swap agreement.
"The future of economic cooperation between the two countries is very bright," Wen said. "China is Pakistan's all-weather strategic partner."
Pakistan regards China as its closest ally and the deals as incredibly important to a moribund economy, which was dealt a massive blow by catastrophic flooding this year and suffers from sluggish Western investment.
The poverty-stricken country is reliant on China's clout to offset the perceived threat from rival India and rescue its economy.
But the fresh trade deals with Pakistan were dwarfed by those signed on Wen's trip to India, where he and his 400-strong delegation signed deals to double trade to 100 billion dollars a year by 2015.
Wen pledged Sunday that "China will remain steadfast in its support to Pakistan and will expect the same from the international community".
"The people of Pakistan will surely overcome (their) difficulties," he added.
Though not specifically mentioned, behind-the-scenes talks had been expected on China building a one-gigawatt nuclear power plant as part of Pakistani plans to produce 8,000 megawatts of electricity by 2025 to make up its energy shortfall.
The nuclear-armed Muslim nation, with a population of 167 million, produces only 80 percent of its electricity needs, starving industry that has slumped in the face of recession and three years of Taliban-linked bombings.
Pakistan imposed blanket security for Wen's visit, which coincided with a public holiday and the weekend, determined that suicide attacks and bombings that have killed 4,000 people since 2007 would not mar the occasion.
"Pakistan has rendered invaluable sacrifices in the war against terror," Wen said, urging the international community to respect Islamabad's efforts after leaked diplomatic cables showed US officials doubt the commitment of Pakistani politicians to fighting the Taliban and al-Qaeda.
"We should not link terrorism to any specific religion or nation, and avoid pursuing double standards while dealing with the issue. We should rather focus on the root causes of terrorism and ways to eliminate them," he added.
Wen inaugurated a 35-million-dollar cultural centre built as a monument to Pakistani-Chinese friendship and held talks with opposition leader Nawaz Sharif and senior figures in the military, which depends on China for hardware.
But local analysts recognise that China's support comes at a price -- a price that could increase as Beijing edges closer to superpower status.
"China will expect Pakistan to be more forthright in counter-terrorism," said political analyst Hasan Askari.
"It has worries about militancy in western China", where it wants to develop Kashgar city into a major industrial and economic centre, he added.