"People smuggling is a trans-national crime that grossly undermines a country's sovereign right to determine who crosses into its territory. It circumvents border security and threatens the integrity of the immigration system, it also puts the lives of those who are smuggled," Mr Guy said.
New Zealand would continue to fulfil its obligations through the United Nations refugee process, he said.
"The bill I am introducing today balances protecting our borders, and upholding our international obligations."
Mr Guy said the proposed mandatory detention period would enable officials to look into the backgrounds of illegal immigrants to assess whether they posed a risk to public safety.
Labour opposed the bill, and accused the Government of pushing the legislation up the order paper to distract from the ongoing Kim Dotcom donation saga with Act leader John Banks.
Labour MP Charles Chauvel said people were quite rightly asking why Parliament was dealing with the issue of boat people at this time.
"It is difficult to escape the conclusion that it is because of the scandals that the National Party are facing and having to manage at the moment," he said.
"This bill addresses an issue that simply isn't before New Zealand as a threat at the moment, it is a waste of the time of the Parliament."
Fellow Labour MP Darien Fenton described the legislation as "one big over reaction to a non-existent problem".
"The Government is determined to divert our attention from the real issues by talking up what they believe is a populist move."
The Greens, New Zealand First and the Mana Party also opposed the bill.