The US Senate looks likely to be dominated by Republicans.
Reuters commentator Andy Sullivan said a divided Congress could prevent Biden from enacting major priorities, such as expanding healthcare, fighting climate change and providing aid to millions whose lives have been upended by the coronavirus.
Biden has said on his first day in the White House, he would issue a national strategy to respond to Covid-19 that would probably include a mask mandate and clearer guidance on testing and school reopenings.
He has also promised to work more productively with health officials that Trump ignored, such as the nation's top infectious-disease expert, Dr Anthony Fauci.
Former New Zealand diplomat and trade deal negotiator Charles Finny said New Zealand could expect a "more conventional presidency" from Biden than was seen with Trump.
However, Biden might not be able to achieve all that he wanted with a Republican majority in the Senate, Finny said.
Biden had supported the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), but it was uncertain whether he could get his party to agree to the US joining the trade agreement with New Zealand and other nations.
"He would be much more likely to join this agreement than a second Trump presidency," says Finny.
Victoria University professor of strategic studies Robert Ayson said the Biden administration would change the US "tone" towards international institutions.
"New Zealand will find in America a partner that is much closer on supporting multilateralism," says Ayson.
"Even though Mr Biden will want to take the US back into the Paris Climate Change Accord, he's going to need the Republicans if he wants to spend some big money on climate change mitigation.
"That's going to be the big issue."