SOURCE: AL JAZEERA AND NEWS AGENCIES
His comments on Monday came shortly after taking the oath of office to become Turkey's first executive president with increased powers after his election victory last month.
"In the new era, Turkey will improve in every field, including democracy, fundamental rights, freedoms, economy and large investments," Erdogan said in his speech at the presidential palace in the capital, Ankara.
Monday's inauguration concluded the transition from a parliamentary system to an executive presidency, in line with the constitutional changes approved in a referendum in April 2017.
"Turkey is leaving behind a system which cost the country politically, socially, economically," Erdogan told the crowd, comprised also of dozens of foreign leaders and dignitaries.
"We will try to be worthy of our nation, aware that we are not only [the government] of our supporters, but all 81 million Turkish citizens," he added.
Under the new system, Erdogan leads the state's executive branch and has the right to appoint and dismiss vice-presidents, a newly introduced position, as well as ministers, high-level officials and senior judges - without parliamentary approval.
The 64-year-old also has the power to dissolve parliament, issue executive decrees and impose a state of emergency. The prime ministry will not exist in the new system.
Later on Monday, Erdogan announced his new cabinet, in which he named his son-in-law, Beraat Albayrak, as treasury and finance minister.
Mevlut Cavusoglu stayed as foreign minister, while Suleyman Soylu kept his position as interior minister.
Other members, including Vice-President Fuat Oktay, were former bureaucrats, NGO leaders, business people and advisers.
He has repeatedly stressed that a powerful executive presidency will create a stable environment that will allow the country to take "steps for the future in a stronger manner".
"The whole mark of the new system is consolidation and predicated upon the rhetoric of efficiency in the decision-making process, in the face of the challenges lying ahead," Ahmet Kasim Han, a professor with Istanbul's Kadir Has University, told Al Jazeera.