US Republican Senator John McCain acknowledged that Syrian President Bashar al-Assad has gained the upper hand in fight against foreign-backed militants. In an interview with CBS\'s Face the Nation on Sunday, McCain said, \"We are seeing unfortunately a battlefield situation where Bashar Assad now has the upper hand,\" press tv reported. McCain, who last week surreptitiously visited Syria, urged the administration of President Barack Obama to send heavy arms and logistic aid to Syrian rebels, claiming that the longer the US waited the more the situation was unraveling. He added that Assad is unlikely to step down, which is what the US and its allies want him to do. On Friday, McCain said the Syrian militants are in dire need of \"ammunition and heavy weapons\" as the government troops are gaining ground in the crisis-hit country. \"There\'s no doubt that they (the militants) need some kind of capability to reverse the battlefield situation, which right now is in favor of Assad,\" he said. McCain, who is a member of the Armed Services and Foreign Relations committees, has been an outspoken supporter of arming the militants in Syria, a stance the Obama administration has shied away from adopting officially though there have been reports of the US role in coordinating the shipment of arms to the militants through Turkey and Jordan. The Syria crisis began in March 2011, and many people, including large numbers of soldiers and security personnel, have been killed in the violence. The Syrian government says that the chaos is being orchestrated from outside the country, and there are reports that a very large number of the militants are foreign nationals. Assad said on May 23, \"Syria is determined to tackle terrorism and those who support it regionally and globally, and to find a political solution to the crisis.\"