washington (cnn) the top united states commander of u.s. and nato forces in afghanistan told congress he has provided his chain of command with options for the drawdown of troops this year that would give both u.s. and afghan leaders flexibility as the security situation evolves on the ground.









while the united states has close to 10,000 u.s. troops currently in afghanistan following the end of combat operations at the beginning of the year, the obama administration has already announced plans to draw that number down to 5,500 by the end of this year.









gen. john campbell told the senate armed services committee on thursday his recommendations deal with both the "glide slope" and "locations" for where to make withdrawals as the summer fighting season in afghanistan gets underway.









"i have provided options on adjusting our force posture through my chain of command," campbell said, adding that he "absolutely" favored the options without elaborating on their specificity.









"i think i provide some options both for [afghan president ashraf] ghani and for my senior leadership here to take a look at what would allow us the flexibility to continue to get after the [train, advise and assist] mission and the [counterterrorism] mission" in afghanistan, he said.









there are currently 9,800 u.s. troops in afghanistan, and an additional 3,000 from other nato partner nations.









campbell told the committee he was "concerned" about the coming summer season, when fighting with the taliban typically reaches its highest levels, because it will be the first fighting season for afghan forces on their own without the assistance of coalition assistance.









"we're doing everything right now in the winter campaign to get them ready to do that," he said, in reference to the ongoing training and advising mission.









many republican leaders on capitol hill have voiced their concern over both the pace, and specific time frame, laid out by the obama administration for the additional drawdown of u.s. troops. some are drawing parallels to the quick removal of u.s. forces in iraq at the end of 2011, and the deteriorating condition that followed.









"a lack of presence creates a vacuum, and we've seen what fills that vacuum in syria and iraq," sen. john mccain, chairman of the committee, said in his remarks. "the ungoverned spaces will allow terrorists to foment the same disaster in afghanistan as we have seen in iraq -- growing instability, terrorist safe havens and direct threats to the united states."









and as the drawdown of the u.s. presence envisions an eventual consolidation of the u.s. footprint to kabul, and the american embassy there, mccain says afghan officials have also voiced concern over the strategy.









"a group of us met with president ghani over the weekend, and he was very strong and adamant that this current plan will put the nation in danger. and i hope that our leadership will pay attention to him," mccain said.









beyond kabul and bagram, where the american presence in afghanistan is largest, the u.s. still maintains tactical advise and assist teams in mazar-i-sharif, herat, kandahar, jalalabad and gamberi. when the u.s. draws down to the final numbers in the current plan, the presence will be restricted mostly to kabul.









"the taliban don't have the d-30 howitzers, they don't have the unarmored humvees, they don't have the mi-17s, they don't have the intel fusion," campbell said, voicing confidence that with continued training and good leadership, the afghan security forces would be able to keep the country stable.









senators also expressed concern about isis gaining ground in afghanistan, especially following a u.s. drone strike earlier this week that killed a senior taliban commander who has also expressed fealty to isis.









"you do have some of the taliban breaking off and claiming allegiance toward isis," campbell said, attributing it partly to a feeling of disenfranchisement on the parts of some taliban members who may be looking to use isis tactics as a way to exploit media attention.









"it is a concern to president ghani, therefore, a concern to me," he said. "but we continue to work that with our afghan partners and to make sure that we understand where this is going inside of afghanistan and pakistan."









campbell called the isis presence in afghanistan "nascent" but said their presence represents "more of a rebranding of a few marginalized taliban, but we're still taking this potential threat, with its dangerous rhetoric and ideology, very, very seriously."
u.s. provides options for drawdown of forces in afghanistan amid isis fears
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