"The Syrian Government is welcoming Iranian help and Hezbollah help," a senior state department official said on Tuesday ahead of US Secretary of State John Kerry's planned visit to Amman the following day.Speaking at a special briefing via teleconference, the official stated that the US knows that Iran and Hezbollah cooperate in a number of countries, "not just in Syria. And so it is not a surprise that Iran would be there with Hezbollah on the ground. We do have consistent reports of Hezbollah fighters on the ground."Commenting on Hezbollah's presence, the official stated that the US have reports "from several of the commanders that Hezbollah fighters are directly engaged in fighting literally on the streets."The official added that the Syrian opposition had been invited to the meetings in Amman on Wednesday, which are part of a broader American effort to resolve the crisis in Syria. Kerry is planning to meet the same group of countries and foreign ministers with whom he met in Istanbul on April 20th.