The latest from Greece's financial crisis (all times local):
The U.S. Treasury Department says Secretary Jacob Lew is "encouraged by reports of some progress" in Brussels at an emergency summit of eurozone leaders about Greece.
Lew noted that Greece is showing signs of "political will to implement difficult reforms."
In a statement issued on Sunday, Lew urged all sides to show flexibility.
He said that rebuilding trust between Greece and its creditors requires a tradeoff between Greek reforms and "measures" to ensure Greece's debt load is manageable.
Another issue facing the eurozone's 19 leaders is whether Greece needs debt relief.
A draft document sent to leaders acknowledges "serious concerns" over the sustainability of Greece's debts but there doesn't appear to be a consensus on what to do.
The issue, like the idea of a temporary Greek exit from the euro, was bracketed in the document obtained by The Associated Press, meaning it was passed to leaders for their consideration.
The Greek government has made debt relief a key plank of its negotiating strategy over the past few months.
Greece's debts stand at around 320 billion euros ($355 billion), or a staggering 180 percent of the country's annual GDP. A direct cut is unlikely but Greece could get longer repayment schedules or cuts in the interest rates it pays on those debts.
Greek Prime Minister Alexis Tsipras was meeting with French President Francois Hollande and German Chancellor Angela Merkel during a break in discussions at the emergency meeting of the eurozone's 19 leaders.
A Greek official gave no further details about the meeting, which also included Donald Tusk, who chairs meetings of European leaders.
Sunday's summit was dealing exclusively with Greece, which desperately needs a deal with European creditors to stave off immediate financial collapse and the country's potential exit from the euro.
But any deal looks like it will require the Greek government to impose tough austerity measures.
The Greek government appears to have accepted a raft of demands from European creditors that it had previously condemned.
Among a series of proposals that made it into a draft document sent to eurozone leaders, Greece has accepted that officials from the creditor institutions will have some sort of base in Athens.
It remained unclear whether that ability "to work on the ground" will be similar to the hands-on oversight the country underwent after the country's initial bailout in 2010. Many in Greece hated what they considered foreign meddling in their affairs.
Elsewhere in the eurogroup document obtained by The Associated Press, Greece has agreed to carry out "ambitious" pension and market reforms, and "significantly" scale up its privatization program.
According to the document, the Greek government has agreed to legislate a first set of measures by Wednesday.
A temporary Greek exit from the euro is up for potential discussion at this evening's summit of the eurozone's 19 leaders.
At the conclusion of a 4-page draft document of proposals put to leaders and obtained by The Associated Press, eurozone finance ministers said Greece should be offered "swift negotiations on a time-out from the euro area with possible debt restructuring" if no bailout deal is agreed.