"That's why the number has increased so fast now that links have been restored with the cities and counties."
As the search for survivors continued intensively on Friday, four people were reportedly pulled out alive.
Four days after the quake, Chinese CCTV showed pictures of a five-year-old boy, looking weak and bruised, being taken from the rubble, bandaged and strapped to a stretcher.
Meanwhile, a 23-year-old nurse was rescued from the ruins of a hospital, and two survivors were found buried together beneath a collapsed office building in the shattered district of Beichuan, state news agency Xinhua reported.
Mr Wen, who has been in the area since the earthquake struck, said the focus of the effort was still reaching survivors.
"Saving lives is still our top priority, as long as hope of survival still exists," he said.
The Chinese president's presence in the region appears to reflect the level of government concern over the scale of the disaster.
"The challenge is still severe, the task is still arduous and the time is pressing," said Mr Hu.
"We must make every effort, race against time and overcome all difficulties to achieve the final victory of the relief efforts."
A student is helped to walk free after being trapped for 80 hours
He was speaking after arriving in Mianyang, one of the cities worst-hit by the 7.9-magnitude earthquake, where he was to view the relief efforts and meet troops and medical personnel.
The first foreign rescuers have now arrived in the devastated region.
Thirty-one Japanese experts arrived on Friday morning, state media said, and a second team with sniffer dogs was due there later in the day.
Taiwan, Russia, South Korea and Singapore are also sending teams to help in the rescue effort.
Troops have now reached all of the affected areas, state media says. It adds that about 159,000 people were injured in the quake and 4.8 million people have been relocated.
Seven schools, including two nursery schools, collapsed in the town of Mianzhu alone, burying more than 1,700 students.
In Hanwang town, about 700 students were buried when Donqi middle school collapsed.
The BBC's James Reynolds in Hanwang described seeing rescuers emerge from a building carrying two bodies, and watching parents wait at the school, hoping their children would come out alive.
More than 200,000 houses have collapsed in Sichuan province, while more than four million have been damaged in some way, Xinhua said.
In Mianzhu, one of the worst-hit towns, one woman said the focus should switch to caring for the survivors.
"The focus is on saving lives, and they say food and a place to live are small issues as long as you're alive," Fan Xiaohua told Reuters news agency.
"In fact, they are very big issues right now," she said.
While the government says the search is still the priority, it is stepping up the effort to get aid to the millions of people displaced or cut off by the disaster, says the BBC's Dan Griffiths in the Sichuan capital Chengdu.
Tens of thousands of Chinese troops and police are in the region to help with relief efforts but damage to roads is making it difficult to get to the worst-hit regions.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.