Jarba, head of the Syrian National Coalition, has said he would ask the US administration for anti-aircraft weapons to battle daily barrel bombings unleashed by Syrian President Bashar al-Assad and help change the balance militarily on the ground.
US officials privately acknowledged he made the request in talks with Kerry at the State Department, but they refused to be drawn on the response.
"I have nothing to announce in terms of any change in our position," said Psaki, referring to the long-standing policy of the US administration to provide only non-lethal military support such as communications equipment, body Armour and night-vision goggles.
"We are continuing to build the capacity of the moderate opposition, including through the provision of assistance to vetted members of the moderate, armed opposition," she said.
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It is understood that Jarba will also meet with US President Barack Obama during his eight-day trip to the US which ends on May 14.
His visit comes as the last rebels pull out of the centre of the battleground city of Homs, handing a symbolic victory to Assad ahead of controversial elections next month.
Jarba Wednesday slammed the polls saying Assad wanted to "run for office on the dead bodies of Syrians" in a three-year conflict which has now claimed more than 150,000 lives.
"We are committed to do our part to support the moderate opposition in its efforts to provide a legitimate voice to the aspirations and hopes of the Syrian people," he added.
And he praised Jarba and the SNC for building "an inclusive and moderate institution" committed "to the protection of all people, all minorities, all rights within Syria.