Pakistan's army chief congratulated the country on Saturday for the "successful conduct" of its national elections, saying the nation needed "stable hands" to move on from the politics of "anarchy and polarisation".

The nuclear-armed South Asian nation voted on Thursday in a general election that remains undecided, as it struggles to recover from an economic crisis and battles militant violence in a deeply polarised political environment.

The Chief of Army Staff of Pakistan "wishes that these elections bring in political and economic stability and prove to be the harbinger of peace and prosperity for our beloved Pakistan", army chief Asim Munir said in a statement released by the media wing of the military.

The United States, Britain and the European Union on Friday each expressed concerns about Pakistan's electoral process in the wake of Thursday's vote, urging a probe into reported irregularities.

Former prime ministers Nawaz Sharif and Imran Khan both declared victory on Friday.