( CNN ) -- The July 2011 deadline to begin withdrawing U.S. troops from Afghanistan is unrealistic and unhelpful , Afghan Ambassador Said Tayeb Jawad told CNN 's `` State of the Union '' Sunday . `` First , if you over-emphasize a deadline that is not realistic , you are making the enemy a lot more bold , '' Jawad said . `` You are prolonging the war . That deadline should be realistic . The line should be based on the reality on the ground and we should give a clear message to the enemy , to the terrorists who are a threat to everyone , that the United States , NATO , Afghans are there to finish this job . '' He continued , `` If that 's not the feeling , we lost the support of the Afghan people , and also make the neighboring countries of interest a lot more bolder to interfere in Afghanistan . '' President Barack Obama and Gen. David Petraeus , who has replaced Gen. Stanley McChrystal as the top U.S. commander in Afghanistan , have said they would begin withdrawal in July 2011 depending on conditions on the ground . Appearing on ABC 's `` This Week , '' Sen. John McCain , R-Arizona , questioned the wisdom of a firm deadline to start withdrawing forces . `` I 'm all for dates for withdrawal , but that 's after the strategy succeeds , not before , '' said McCain , the Republican presidential candidate in 2008 who was in Afghanistan for the Fourth of July weekend . For now , McCain described the strategy as one that has n't gone as well as hoped . `` The president should state unequivocally that we will leave when we have succeeded , '' he said . `` If you tell the enemy that you 're leaving on a date certain , unequivocally , then that enemy will wait until you leave . '' McCain 's GOP colleague , Sen. Lindsey Graham of South Carolina , echoed those thoughts in a separate interview from Afghanistan broadcast on the CBS program `` Face the Nation . '' `` If you send a signal to your enemy you 're going to leave at a certain date , they 'll wait you out , '' Graham said . However , he expressed optimism that the counterinsurgency strategy now being led by Petraeus can show progress in turning over security to Afghan forces in some areas by July 2011 . `` I do believe next summer we can have transition in certain parts of Afghanistan , '' Graham said . `` Other parts will still need fighting and a firm commitment . '' Overall , Graham said , he found morale on the ground `` pretty good '' as Petraeus assumed command of the mission . His trip coincides with the visit to Afghanistan by Vice President Joe Biden , and Graham said Biden had assured him that any withdrawal of U.S. forces from the country would be `` conditions-based '' instead of launched purely for the sake of getting out without consideration for the status of the mission . Graham joined McCain in urging Obama to clarify the conditions-based approach so that the nation 's allies and enemies understand the U.S. commitment to the war . Last week , some Democrats in Congress supported an amendment to a military spending bill that would have required Obama to give Congress a new intelligence report on Afghanistan by January and a plan for withdrawing troops by April . If Obama fails to carry out his pledge to start bringing troops home by July 2011 , Congress would need to approve additional funding for the war , the amendment said . The measure failed in a late-night vote after the White House threatened to veto the bill if it contained the amendment , but the language showed some restlessness among Democrats about the war strategy .
NEW : Sen. McCain : withdrawl should only begin when conditions warrant it . Democrats and Obama critics say troops should stay until success is assured . U.S. has said withdrawal would start in January . Withdrawal also depends on situation on ground , Obama says .