The trial, being held behind closed doors in Yangon's Insein prison, entered its fifth day on Friday.
According to the New Light of Myanmar Nyan Win told the Japanese foreign minister the incident was organised by "internal and external anti-government forces," a term the government usually uses to refer to pro-democracy groups.
"[I]t was likely that this incident was trumped up to intensify international pressure on Myanmar by internal and external anti-government elements," he was quoted as saying.
Aung San Suu Kyi has been in detention without trial for more than 13 of the past 19 years, and has been charged with allowing a visitor to stay at her home without official permission – an offence punishable by up to five years imprisonment.
Two female members of her National League for Democracy (NLD) party who live with her are also on trial, as well as Yettaw himself.
Yettaw, a Vietnam War veteran from the US state of Missouri, is alleged to have visited her home twice, swimming across Yangon's Inya lake to avoid security.
He was arrested in early May as he attempted to swim back from the second visit.
|Yettaw is said to have been motivated by a premonition of Aung San Suu Kyi's death [EPA]
On Wednesday the trial was shown a video Yettaw allegedly shot at Aung San Suu Kyi's home.
The video had a voice-over, apparently by Yettaw, which was translated into the local language in the courtroom, Nyan Win, one of the opposition leader's lawyers - who is not related to the foreign minister - told reporters.
"The video taken by Yettaw showed the portrait of General Aung San [Myanmar's independence hero and Aung San Suu Kyi's father], a bookshelf and Yettaw himself standing in front of the portrait of General Aung San," he said.
"He was saying he is now in Yangon, at Aung San Suu Kyi's house and that he asked permission to film Aung San Suu Kyi but she refused."
Aung San Suu Kyi's lawyers have also said that she told Yettaw to leave, but that she allowed him to stay for two days after he pleaded that he was too ill and tired to return across the lake.
On Wednesday, Yettaw also offered the first possible motive for his actions, suggesting that he had a premonition someone would try to kill Aung San Suu Kyi.
Aung San Suu Kyi's current period of house arrest had been due to expire on May 27.
Opposition supporters and Western governments critical of Myanmar have condemned the charges against her, saying they are a pretext for the government to keep her detained through national elections it has scheduled for next year.
The government says the vote will mark the culmination of Myanmar's "roadmap to democracy," but critics say the regulations surrounding the election mean it will only cement continued military control.
Myanmar has been under military rule since 1962.
It last held an election in 1990, but the government refused to recognise the results after a landslide victory by the NLD.