The USDP noted that the NLD won 81 percent of the vote in 2015, but just 47 percent in last week’s by-elections.
Burma’s political parties, including the NLD and USDP, wrap up their campaigns for this weekend’s by-election.
Burma’s Union Election Commission has officially opened the application process for candidates to run in by-elections slated for April next year.
The new chairperson of the Union Election Commission is a retired university rector who previously oversaw elections in Meiktila in Mandalay Division.
When US President Barack Obama hosts a meeting of Southeast Asian leaders in California this week, his Burmese counterpart Thein Sein will be notably absent.
Leaders from the Association of Southeast Asian Nations will meet Obama at a summit in the Californian resort of Sunnylands between 15 and 16 February.