Germany is likely to argue that its rising domestic demand and plans to increase public spending show Europe's largest economy is doing what it can, according to European sources familiar with the G-20 agenda.
Babacan said pushing G-20 members to meet previous reform commitments would be key, a strategy he has dubbed: "Keep your word, or explain".
"It has a lot to do with leadership ... Doing the necessary but difficult things," he said.
Coming good on pledges made at November's G-20 summit in Brisbane could add more than $2 trillion to the global economy and create millions of new jobs over the next four years, Lagarde said in her blog post.
Read MoreG-20 chiefs plea for 'cooler heads' in Greek crisis
UBS Chairman Axel Weber said enabling the private sector to help close the financing gap for an estimated $60 trillion to $70 trillion in infrastructure spending needed by 2030 would fuel growth.
Higher capital requirements are limiting banks' ability to invest and regulators should "revisit whether they got that calibration right", the former Bundesbank president told the IIF meeting.
"My key message to policymakers would be very easy—don't work against the private sector, work with it," he said.
The G-20 put together a global stimulus package during the 2007-09 financial crisis but today's challenge is more delicate, with diverging monetary policies a cause of global turbulence.
The U.S. Federal Reserve looks set to raise interest rates this year, a stark contrast to impromptu cuts from India to Australia, Canada to Denmark, as well as China's cut in bank reserve requirements and the abrupt end to the Swiss franc cap.
A senior Canadian official said the G-20 communique would probably emphasize the importance of central bank actions in sustaining demand and said the Fed and Bank of England had voiced support for other central banks' actions to lift growth.
Turkey's own monetary policy may also be in the spotlight. Its central bank is under government pressure to cut interest rates ahead of a June election despite stubborn inflation, with critical comments by President Tayyip Erdogan last week sending the lira to a record low.
Erdogan renewed his criticism of the central bank on Sunday, saying it would be "held to account" if it failed to manage the lira's exchange rate against a strengthening dollar.
A source close to French Finance Minister Michel Sapin said Greece would be discussed, although the situation was very different to a few years ago, with protection mechanisms in place and European markets less sensitive to its woes.
France has also asked to discuss the fight against terrorist financing, an important topic for Turkey given fighting with Islamic State militants taking place just over its southern borders in Syria and Iraq.