Former Pakistan prime minister Nawaz Sharif has been holding talks with party colleagues on forming a government after claiming victory in parliamentary elections.
Mr Sharif's last period in office ended in 1999 when he was deposed in a military coup and spent years in jail and exile.
He has been congratulated by US president Barack Obama who says the US is ready to work as an equal partner with the new government.
Unofficial results suggest a big lead for Mr Sharif's Muslim League (PML-N), though he may need support to govern.
Former cricketer Imran Khan, who could be the main opposition leader, said he was pleased with the high turnout but disappointed about reports of rigging.
The ruling Pakistan People's Party (PPP) seems to have been badly defeated
It was one of several secular parties unable to campaign freely due to Taliban attacks.
The election was generally seen as having passed off successfully, but violence during polling on Saturday claimed at least 24 lives, the BBC reports.
An election commission spokesman said turnout had been around 60%. In 2008 it was 44%.