"Nobody stopped me from going there and nobody can stop me unless that country refuses me entry. There's nobody who can refuse me from going," he told the Mail & Guardian on Friday.
News reports from Namibia claimed Swapo leaders intervened to prevent Malema from visiting the country as it might strain relations with the ANC.
According to reports, Malema was invited to deliver the Chris Hawala Inaugural Memorial Lecture at a private event organised by individuals linked to Swapo. Hawala was a youth activist who died in 2008.
The organisers said Malema would speak on the topic "Towards the African Youth Manifesto: Economic Freedom in our Lifetime" on July 5.
Namibian media reported that organisers on Thursday issued a press statement saying the event had been cancelled because of fears for Malema's safety.
"It should be noted that Malema confirmed his coming to Namibia but the committee fears for his security and the impact it will have on the youth league and its leaders," they said in the statement. Organisers blamed the media for linking the event to Swapo and its youth league.
The New Era newspaper said the cancellation of the visit was prompted mainly by "the embarrassing linkage of the controversial Malema to the Swapo Party and its youth league".
According to the Namibian: "Swapo leaders, among them President Hifikepunye Pohamba, were concerned that the Malema visit might sour relations between Swapo and the ANC, as it was likely that the expelled former youth leader would have used the forum to criticise South African President Jacob Zuma".
But Malema told the M&G he was unaware of any invitation to speak in Namibia and had no plans to go to there in the first place.
"Nobody has invited me … I don't know anything about being in Namibia next weekend," he said.
"I'm just hearing these things from you, so I had no idea. They [the organisers] should tell you who they spoke to and we can follow up."
The M&G was unable to contact organisers for comment.
Malema has fallen from the public eye since the ANC's national disciplinary committee of appeals upheld his expulsion from the party in late April.
While ruling party delegates frantically debated the ANC policy documents in Midrand this week, Malema was relegated to watching the events on television from a guesthouse in the suburbs.