Rome (CNN) -- Meeting in Rome with Jordanian Foreign Minister Nasser Judeh, Secretary of State John Kerry announced Thursday that the United States would provide an additional $100 million in humanitarian assistance for refugees fleeing the fighting in Syria, bringing the total amount of aid to $510 million.
Kerry also said that he is working to bring all parties together to create a transitional government and that Syrian President Bashar al-Assad would not be part of that government.
Jordan, which is being inundated by a wave of Syrian refugees, will receive nearly $43 million, which will support United Nations humanitarian programs in the region.
Kerry said the fourth-largest "city" in Jordan today is a tent city filled with Syrians fleeing their country, adding that "Jordan feels the impact of what is happening more than any other country."
The foreign minister gave a bleak assessment, saying the 525,000 refugees make up 10% of Jordan's population. He said the number is expected to increase to 20% or 25% by year's end, and then to 40% of the population by the middle of 2014. "No country can cope with the numbers that are as huge as I described," he said.
The minister said he was "encouraged" by Kerry's meetings in Moscow this week, at which the U.S. and Russia agreed to push for an international conference on Syria that would possibly be held by the end of the month and include, for the first time, representatives of the Syrian government as well as the opposition fighting that government.
Judeh said he was leaving Rome for meetings in Moscow.
Kerry said he had asked Robert Ford, the U.S. ambassador to Syria, to travel to Istanbul to confer with opposition leaders. He said that on Wednesday, he discussed the plan for the conference by phone with the foreign ministers of most of the countries involved in trying to find a political solution, as well as with U.N. Secretary General Ban Ki-moon.
"There's a very positive response and very strong desire to move to this conference," he said, "and to at least exhaust the possibilities of finding a political way forward."