The Norwegian foreign ministry called the decision “regrettable”.
“Despite our differences on several issues, Norway wishes to keep the dialogue open with Venezuela and will continue to work in this direction,” a ministry spokeswoman said.
She added that the Nobel Prize “is independent of the Norwegian government”.
Machado has for years been campaigning against Maduro, whose 12-year rule is viewed by many nations as illegitimate.
She has been forced to live in hiding for much of the past year.
In honouring her achievement, Nobel chairman Jørgen Watne Frydnes called Machado a “key, unifying figure in a political opposition that was once deeply divided… in a brutal authoritarian state that is now suffering a humanitarian and economic crisis.”
Machado told BBC Mundo her award was “like an injection” for her political movement. “It infuses energy, hope, strength on the Venezuelan people because we realise that we are not alone,” she said.
Caracas also closed its embassy in Australia while opening new outposts in Zimbabwe and Burkina Faso, which it called “strategic partners in the fight” against “hegemonic pressures”.
Venezuela’s closure of embassies in two close US allies comes after weeks of heightened tension between Caracas and Washington.
The US military has destroyed at least four boats that it said were carrying narcotics from Venezuela to the US, killing at least 21 people on board, in what the Trump administration calls a war on drugs.
The strikes have attracted condemnation in countries including Venezuela and Colombia, with some international lawyers describing the strikes as a breach of international law.
The last time Norway suffered a diplomatic blow over the Nobel Peace Prize was with China in 2010, when it was awarded to political dissident Liu Xiaobo. Beijing suspended trade and other relations, and only normalised ties with Oslo six years later.