Greece must "quickly implement" the terms of a tough EU bailout agreed in July, newly re-elected left-wing Prime Minister Alexis Tsipras said on Friday.
"We face the obligation to quickly implement what has been agreed," Tsipras told his new government's inaugural cabinet meeting.
In the closing days of Tsipras' last administration, Athens signed up to more tax hikes and public spending cuts in return for a three-year, 86-billion-euro ($96-billion) EU bailout.
Stonewalling creditor proposals with an anti-austerity referendum in July, the 41-year-old leader brought Greece to the brink of exiting the eurozone before backing down.
The U-turn split Tsipras' ruling Syriza party and forced him to step down, but he comfortably won re-election on Sunday with a pledge to mitigate the impact of the bailout.
"We are aware of the difficult points of the deal... we know how to find the right antidote where there are side effects," Tsipras said on Friday.
In a positive signal to creditors, Tsipras brought back the team that brokered the bailout -- with Euclid Tsakalotos returning as finance minister and top negotiator George Chouliarakis appointed junior finance minister.
In the coming weeks, the government must present an overhaul to make the country's underfunded pension system viable and introduce sweeping tax hikes.
Greece's new parliament, expected to convene on October 1, will also have to revise the 2015 budget, taking into account the reforms, including taxes on farmers' income that are set to double by 2017.
The government must also finalize a procedure to recapitalize Greek banks by December, before new EU-wide bank rescue regulations that could affect depositors come into play in 2016.
And Tsakalotos will have to move quickly to remove capital controls imposed in June to avert a deposit run.
In late October, the lenders will conduct an audit to determine whether Athens is abiding by the reform program. The release of a three-billion-euro ($3.3-billion) tranche of aid depends on its findings.
"It is critical not to lose an inch from the ground gained in the deal," Tsipras said, telling ministers they had "no time" to lose, and urging them to stay off television.
"I call you to immediately halt your constant television appearances ... I selected you as ministers to solve problems, not to staff talk show panels," the premier said.
Greece's other immediate challenge is to find accommodation for refugees and migrants that continue to stream into the country, on the heels of over 310,000 people that have arrived since the beginning of the year.
The UN refugee agency plans to open a 1,000-bed camp in the town of Idomeni on Greece's border with Macedonia, the main transit point for northern Europe.
Some 5,000 people daily pass through Idomeni on the Balkans route towards prosperous northern European economies, more than double the numbers seen a few weeks ago, according to police.
Registration centers will also open on the Aegean Sea islands of Lesbos, Kos and Leros, where tens of thousands of mainly Syrian refugees and migrants land from Turkey.
Tsipras has criticized the heavy-handed response of eastern EU states such as Hungary, where tear gas and water cannon has been used to push back migrants.
"The identity of Europe is at stake," Tsipras said, adding that his administration was "against the logic of turning European borders into battlefields and our seas into watery graveyards."