Jonas Gahr Stoere, Norway's foreign minister, said the Palestinian coalition was a "historic event" whose alternative would have been continued violence in the Gaza Strip and the West Bank.
Stoere told a news conference: "Norway will deal with members of the new Palestinian government as representatives of a broad and representative unity government."
He said it was "essential that the unity government gains control of the security situation ... and that the rocket attacks on Israeli areas cease".
"This is just a ploy to regain international hand-outs with smoke and mirrors"
LeotheIsaurian, Detroit, US
Send us your views
"We particularly call on Israel to take a constructive approach to the unity government, for example, by releasing withheld Palestinian revenues from taxes and fees and by increasing the freedom of movement for the Palestinian population," he said.
Norway's left-of-centre government has had warm relations with the Palestinians and avoided using the word sanctions or boycott after Hamas gained power, although it placed "restrictions" on aid and other political contacts.
"On the basis of the new government's political platform, Norway expects the Palestinian authorities to respect basic international standards as regards compliance with previously concluded agreements, renunciation of violence and recognition of Israel's right to exist," Stoere said.
Stoere praised efforts by Mahmoud Abbas, the Palestinian president, to form the new government as well as efforts by Washington in forging ahead with peace efforts.
"We will continue to support president Abbas actively in his efforts to establish an independent Palestinian state free of occupation," Stoere said.