"We will be rebuilding and reshaping the party. We'll go forward. We are confident we will be back to make a difference for New Zealand."
Two of the leadership contenders - David Parker and David Cunliffe - were at the function and both refused to discuss whether Mr Goff would have their support next week.
Mr Goff received a loud welcome from the 200 supporters gathered. He told supporters he believed Labour had fought a strong campaign.
"The decision tonight was not a decison we wanted but I believe we can leave here with our heads high. Politics is about leadership, it's about fighting for the things that are right for our country.
"Let's go from here tonight determined to rebuild our strength in Parliament, to make our party stronger."
"The people have made their decision and we treat their decision with humility and respect."
Mr Goff told Labour supporters he had rung National leader John Key and conceded, wishing him the best for the three years ahead.
He said Labour would support a National-led government when it made decisions that Labour agreed with, but it would continue to fight on policies such as asset sales, believing there was no mandate for it.
"It wasn't our time this time, but we are members of a great political party. For 95 years, Labour has taken this country forward. It might not have been our time this time, but our time will come again and we will be ready to take New Zealand forward."
Mr Goff said his first thank you was to New Zealanders who "kept the faith" and voted for Labour. His second thank you was to his wife Mary.
He also congratulated the new MPs for Labour, including Rino Tirakatene, Andrew Little, David Clark and Megan Woods.
He reserved particular congratulations for Damien O'Connor for taking back the West Coast Tasman seat from National's Chris Auchinvole.
However he also voiced his "sadness and regret" for the MPs who did not make it back, hoping many would be able to return in the future.
He said some of the MPs Labour had lost - such as Stuart Nash and Kelvin Davis - were talented and the party would work to get them back into Parliament in the future.