The new Northern Ireland Secretary has promised to help build stability and peace in the North.
Theresa Villiers, MP for Chipping Barnet, takes over from Owen Paterson following a Cabinet reshuffle by British Prime Minister David Cameron.
Mr Paterson has moved to the Department for the Environment, Food and Rural Affairs.
Ms Villiers takes up the post as the Northern Ireland Office considers reforms to powersharing structures at Stormont and comes under pressure to deal with growing tensions over parading in the North.
She said: "Huge progress has been made in Northern Ireland over recent years.
"As the headlines in the past few days demonstrate, however, we still have some way to go if we are to overcome the divisions in society and build a genuinely shared future."
She said the British government would stand by agreements made over the past two decades and political institutions established.
She added she was acutely aware of the need to rebalance the economy and the British government would put pressure on those who resort to terrorism and violence to pursue their objectives.
"So I look forward to working with the Executive, political parties and people from right across the community to build a stable, peaceful and prosperous Northern Ireland for everyone. This is a great opportunity which I relish," she added.
Ms Villiers, 44, was an MEP before becoming a Conservative MP.
She attended Oxford and is a former barrister.
She has taken an interest in aviation policy, objecting to the expansion of airports in the south-east of England and supporting high speed rail links.
Mr Cameron appointed Ms Villiers to his shadow cabinet in 2005 as shadow chief secretary to the British Treasury.
At David Cameron's first reshuffle in July 2007, she was given her own portfolio - transport.
Mr Paterson was shadow spokesman on agriculture and fisheries from 2003 to 2005 and is from a farming background. He enters his new ministerial role holding strong views on EU policy over what will be his area of responsibility.
During his time as Northern Ireland Secretary his most high-profile project was his effort to secure devolution of corporation tax powers to the North, believing that would help rebalance an economy heavily reliant on the public sector, but that potential change has yet to be finalised.
He was accused by unionists and republicans of interfering in Stormont politics when he criticised their failure to agree a strategy on combating sectarianism.
Mr Paterson was credited over the Government's widely welcomed handling of the Saville Inquiry findings into the death of 14 civil rights protesters in Derry on Bloody Sunday in January 1972 when paratroopers opened fire.
However he faced criticism over his handling of the findings of an inquiry into the killing of Catholic solicitor Rosemary Nelson at her home in Lurgan, Co Armagh, in 1999 and over the British government's failure to allow an inquiry into the loyalist murder of Belfast solicitor Pat Finucane in 1989.
Ms Villiers is largely unknown in the North, but could arrive as early as tomorrow to begin work.
Sinn Féin president Gerry Adams said: "There are a range of outstanding issues arising from the Good Friday, St Andrews and Hillsborough Agreements which need to be progressed, including a Bill of Rights for the North, as well as other important matters like corporation tax and cross-border economic development."
SDLP leader Dr Alasdair McDonnell said: "I look forward to working with her across the wide range of issues we will face, most particularly on the economic front and hope that she can move the issue of corporation tax forward."
First Minister Peter Robinson said he wants to meet the new Northern Ireland Secretary as soon as possible.
"I look forward to working with Theresa on a wide range of outstanding issues which require her urgent attention," he said.
"I thank Owen for his efforts as Secretary of State for Northern Ireland over the past five years and wish him every success in his new post as Secretary of State for Environment."
Glyn Roberts of the Northern Ireland Independent Retail Trade Association called on Ms Villiers to prioritise the corporation tax issue.
"We look forward to working with Theresa Villiers and would encourage her to make a priority of moving forward the current talks on Corporation Tax and indeed working with devolved Ministers on establishing Enterprise Zones in Northern Ireland," he said.