"The support provided by the US government is especially important for Greece, for the eurozone, for the international economy and for the global economic governance," he told reporters Monday following meetings with International Monetary Fund managing director Christine Lagarde and US Treasury Secretary Timothy Geithner.
Venizelos did not say just how much support he was seeking from the IMF -- where the United States has a huge say on its emergency loans.
But he did say supporting Greece and the eurozone was "in the interest of the United States as the leading power in the global economy."
"Their support, especially through the IMF, is vital for us, but also for international monetary stability."
The IMF has yet to say how much money it will commit to the new 159-billion-euro ($229 billion) rescue plan the European Union crafted for Greece last week.
"We can breathe easier but now the key point is to implement the program," Venizelos said.
"The eurozone is always open to the participation and assistance of the IMF, which has a vast experience and know-how. This is the real reason of my visit here in Washington today."
The IMF already made its largest-ever bailout loan, 30 billion euros, to the first rescue of Athens, and there had been some concern that the Fund would be resistant to adding money to a new program.
Official Treasury and IMF statements about the meetings Monday offered little concrete about the discussions.
The Treasury said in a statement that Geithner "welcomed the progress Greece has already made toward strengthening its public finances and underscored the need for continued and full implementation of the program."
The United States is not a part of the new rescue for Greece, but as the most powerful country, voting-wise, on the IMF board, it has oversized power in determining the Fund's most important programs.
Meanwhile the Institute of International Finance, which coordinated the private banks that agreed to roll over Athens's debt at a loss to reduce its debt payments and make the second plan work, called IMF participation crucial.
"Let me be clear: Europe knows, the IMF knows, we all know it does not work without continued IMF support," IIF managing director Charles Dallara told reporters in Washington.
Without IMF participation, he said, "I think not only our deal's invalid but Europe's Marshall Plan (the second bailout) (and) the IMF's Greek program too," he said.
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