Xi urged the multi-billionaire to "continue to play an active role in promoting China-US economic and trade cooperation", the official Xinhua news agency said.
'There is never a justification for violence. No excuses, no exceptions: America is a nation of laws,' he said.
The ministry did not specify if the signal was detected from the downed plane's black box.
The Sriwijaya Air Boeing 737-500 plunged into a steep dive about four minutes after it left Soekarno-Hatta international airport in Jakarta on Saturday afternoon.
'One of the few things he and I have ever agreed on,' Biden said. 'It's a good thing, him not showing up.'
Hundreds of gay rights supporters had gathered despite heavy rain near Taipei's parliament as a mammoth legislative debate got underway over an issue that has bitterly divided the island.
More than 1,100 people have died since the central African country last August declared a 10th outbreak of Ebola in 40 years.
It was the first official confirmation that negotiations were being attempted between the government and opposition after a months-long power struggle.
Authorities said 25 people had been found in the rubble, 10 of whom had succumbed to their injuries.
China later announced it suspected Kovrig of spying and stealing state secrets and alleged that Spavor had provided him with intelligence.
