Ms. Suu Kyi declined to say yet if she herself will stand in the election when pressed on the issue, but party spokesman Nyan Win said Suu Kyi intends to run.
The highly anticipated by-election set for April 1 will return Suu Kyi's party to mainstream politics after two decades. In 1991 elections, the then-ruling junta refused to accept a NLD victory, and the party boycotted general elections in 2010 because of restrictions that among other things would have prevented Suu Kyi from running.
That vote lead to a nominally civilian government being installed in March 2011 that has eased restrictions on politics and other matters, and leaders have begun engaging Suu Kyi.
She and Nyan Win spoke to The Associated Press in an interview at the Nobel laureate's residence Thursday.
Most of the 48 Parliament seats being contested in the April vote were vacated by MPs who became Cabinet ministers after the first parliamentary session last January.
With the government's recognition of the NLD, anyone can join and support the political party. Nyan Win said the NLD will start accepting new members on Monday.
Political parties must submit their candidate list for the by-election by Jan. 31.
The military is guaranteed 110 seats in the 440-seat lower house, and 56 seats in the 224-seat upper house, and the pro-military party now occupies 80 percent of the remaining 498 elected seats, so the 48 seats up for grabs, even if the NLD wins them all, will not change the balance of power.
First visit by Britain's Foreign Minister
Britain's foreign secretary urged Myanmar to push its democratic reforms and release all political prisoners as he began a historic trip Thursday to a country that has recently emerged from a pariah status in the West.
Myanmar President Thein Sein greeted Hague in the capital, Naypyitaw, but neither talked to reporters before their meeting. Hague is scheduled to later meet with opposition leader and Nobel peace laureate Aung San Suu Kyi in the main city of Yangon.
In a statement issued before leaving London, Hague said his trip was intended to encourage the "government to continue on its path of reform, and to gauge what more Britain can do to support that process."
Western nations have offered cautious support for reforms that have led to the military junta that had ruled since 1962 taking a back seat and allowing a nominally civilian government to take power in March after winning elections that were boycotted by Suu Kyi's party.
But since then, her National League for Democracy party has joined the political process and said it will take part in upcoming by-elections. Also, the government has released some political prisoners.
Britain believes there are between 591 and 1,700 political prisoners held by Myanmar authorities, though poor record keeping and disputes over the status of captives mean an accurate figure is difficult to gauge.
"We hope to see the release of all remaining political prisoners, free and fair by-elections, humanitarian access to people in conflict areas and credible steps towards national reconciliation," Hague said.
Though Hague's two-day visit signals a shift in relations, Britain won't promise any immediate change in European Union sanctions on arms sales, asset freezes and travel bans — or change a policy that discourages U.K. businesses from trade with Myanmar.
Britain recently pledged 185 million pounds ($289 million) over three years to fund health and education projects — becoming Myanmar's largest bilateral aid donor — but the U.K. channels funds only through nongovernmental groups.
Hague will lay out a series of demands for Myanmar's leadership to meet before Britain considers offering funds direct to the government, or before the EU can lift any sanctions.
"Further steps are needed that will have a lasting impact on human rights and political freedom," Hague said.