Democratic Unionist Party (DUP) leader Arlene Foster has said her party is "listening" after it lost two of the 10 seats it won in 2017.
The party saw its share of the vote drop by more than 5%.
Sinn Féin suffered an even bigger drop in its overall vote share but it took the North Belfast seat from the DUP's deputy leader Nigel Dodds.
"To those who felt unable to support us yesterday, we're listening," Mrs Foster tweeted.
"I know you want to get NI moving again and have an Assembly to fix our schools and hospitals.
"I will be at the Talks on Monday.
"We need a willing partner though."
Earlier, the DUP's Sir Jeffrey Donaldson said unionists were giving away seats "on a plate".
Sir Jeffrey, who was re-elected in Lagan Valley with a reduced majority, said his party had to reflect on its plan for the future.
"Unionists in general are fed up to the back teeth of this inter-unionist squabbling," said Mr Donaldson.
He said there was a "splintering of the unionist votes" in North Down, where the cross-community Alliance Party's Stephen Farry took the seat vacated by popular independent unionist Lady Hermon.
The DUP's Alex Easton and the Ulster Unionist Alan Chambers had also stood for election in the constituency.
Mr Donaldson blamed the Ulster Unionist Party (UUP), and questioned whether it could "seriously continue handing seats on a plate to nationalist representatives".
While the DUP held on in East Belfast with a win for Gavin Robinson - albeit with a much-reduced majority - the party lost a big chunk of its vote across Belfast.
In the South Belfast constituency the SDLP's Claire Hanna ousted Emma Little-Pengelly of the DUP.
The DUP's biggest player at Westminster - Mr Dodds - missed out on re-election in North Belfast.
His seat, which had previously always been held by a unionist, was won by Sinn Féin's John Finucane.
That came after the SDLP agreed not to run a candidate in the constituency for the first time.
Sinn Féin representatives do not take their seats in the House of Commons, where the party has always held a policy of abstentionism.
While it may not have been a great election for unionism, the Alliance Party became the third largest party in Northern Ireland, after the DUP and Sinn Féin.
Alliance leader Naomi Long, who failed to take East Belfast from Mr Robinson, said her party did "exceptionally well" in challenging the two main parties.
"The best performance is always to win the seat but given the mountain we had to climb in East Belfast the fact we came so close is incredible," she said.
Mrs Long said many voters in North Down had switched to the Alliance Party rather than opting for unionist candidates.
In Foyle, there was a landslide victory for SDLP leader Colum Eastwood, who beat Sinn Féin's Elisha McCallion by 17,110 votes - overturning what had been a 169-vote majority.
Congratulations @columeastwood on your impressive victory. I look forward to working with you in the future. It has been an huge honour and privilege to represent the people of Derry. I will continue to fight for Derry tomorrow and every day.— Elisha McCallion (@ElishaMcC_SF) December 13, 2019
"Republicans don't retire" pic.twitter.com/r368pc9L96
Mr Eastwood said people from across Londonderry's political spectrum had elected him as Foyle MP.
"We were winning absolutely everywhere, traditional SDLP areas, areas where Sinn Féin would be stronger, unionist areas.
"But this is not the SDLP's victory; this is about the people of Derry screaming at politicians to get back to work and to go to the places they are elected to go to and represent us."
Sinn Féin's MLA, Raymond McCartney, said lessons had to be learned from Elisha McCallion's defeat but he insisted the party would bounce back
"Where it went wrong is that possibly the SDLP had a stronger message," he said.
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