North Korea in December launched a satellite using a long-range rocket. Similar launches in 2006 and 2009 coincided with the country's first nuclear tests.
A senior official in Seoul said a third test is likely before Park takes office Feb. 25.
"There is a possibility of the North conducting a test before the current administration's term ends, considering its relationship with the incoming government," the senior official said on condition of anonymity. "The North has come too far to step back at this point. It has already finished preparations for a test and is only awaiting a political decision."
Satellite imagery in mid-January of a North Korean nuclear facility indicates signs a third nuclear test may be imminent.
Yonhap reports the test date could be Tuesday, the scheduled date for U.S. President Barack Obama's State of the Union address, or Saturday, the birthday of late North Korean leader Jim Jong Il.