The U.S. and allied defense officials are considering keeping thousands of American troops in Afghanistan beyond the end of 2016, the Wall Street Journal reported Thursday. The officials are reportedly concerned about the plans of White House to scale back the U.S. presence in Afghanistan.

Authorities are reviewing new options that include keeping the current U.S. presence at or near 10,000; reducing it slightly to 8,000; or continuing with the current drawdown plans, the newspaper reported. U.S. Army Gen. John Campbell, the top international commander in Afghanistan, had sent five different recommendations to the Pentagon and the NATO officials, the Journal reported, citing the U.S. and allied officials.

The review is being conducted after some officials feared that too large a cut in the number of troops could cause the Afghan government to come under increased pressure from the Taliban and other militants.

“We will continue to work closely with President Ghani, the Afghan government, and our international partners to ensure that Afghan forces have the capabilities and training necessary to preserve the gains made by the Afghans and the international community over the last 13 years,” a senior administration official told the Journal.

The Pentagon has not issued any formal recommendation on changes in the American troop presence in Afghanistan. Under current plans, the U.S. has to hand its remaining bases to Afghanistan and shrink its forces in Kabul by the end of next year.

In March, U.S. President Barack Obama announced in response to a request from Afghan President Ashraf Ghani that he would keep 9,800 forces in Afghanistan until the end of 2015, instead of reducing them to 5,500.

NATO Secretary-General Jens Stoltenberg told the Journal that a decision is yet to be made over closing bases in the north, east and south of Afghanistan and moving to the next phase of reducing allied troops in Kabul. NATO and the U.S. currently have a combined force of about 13,000 in the embattled country mostly engaged in training and support, assisting the Afghan military and police to better deal with attacks from terrorists.

“We are assessing this very carefully in the alliance. The U.S. is key because it is by far the largest contributor to NATO’s operations in Afghanistan,” Stoltenberg said. “Exactly how we shape the different elements and when we move to different phases, all that remains to be decided. But we have to make decisions in the not too far future.”