Trump said that the U.S. and Italy "are bound together by a shared cultural and political heritage dating back thousands of years to Ancient Rome."
Caldwell is a prominent Houston megachurch pastor who was once President George W. Bush's closest spiritual adviser.
Trump's suggestion about defaulting on the U.S. debt would cause a global financial crisis.
After an initial wave of selling, European stocks and the euro recovered some ground.
Stocks rose to two-month highs, while government bond yields hit their lowest in three weeks.
Samaras needs the backing of 25 more lawmakers to finalise terms for early exit from the bailout
Britain's government will pay off part of the nation's First World War debt as part of a redemption of bonds stretching as far back as the eighteenth century.
Axel Kicillof also said it would be "madness" to pay holdout creditors the 100 cents on the dollar that they were awarded in 2012
For Argentina, it's coming down to the wire—and the chances appear to be growing that it will default on its sovereign debt