Acting Defense Secretary Patrick Shanahan said Thursday the Pentagon has no plans to force allies to pay dramatically higher costs for hosting American forces in their countries, saying reports of a steep increase are wrong.

Shanahan told the Senate Armed Services Committee that allies need to pay their fair share, but compensation comes in many forms, including providing support for war in places like Afghanistan.

U.S. officials earlier this month said the Trump administration was eyeing a plan to make allies pay significantly more, and some reports suggested it could be the full cost of the troops' presence plus an additional 50 percent.

Sen. Dan Sullivan, an Alaska Republican, asked Shanahan about the reports, adding, "are we driving our allies away from us?"

"Senator, we won't do cost plus 50 percent," Shanahan replied, calling the reports erroneous. "We're not going to run a business. We're not going to run a charity."

He added that "not everyone can contribute. But it is not about cost plus 50 percent."

Defense officials have acknowledged that the Pentagon has been asked to gather data on the costs of keeping troops in other countries and how much those nations contribute to the expenses.

President Donald Trump has waged a lengthy, public campaign to get allies to pay more for the costs of U.S. troops within their borders.

Shanahan also told the Senate panel that the United States and its partners in Syria have liberated virtually all the territory the Islamic State group once held.

But he's not declaring victory. The insurgents and local forces are still battling over a small slice of land.

Shanahan said U.S. forces are drawing down in Syria but will maintain a presence to prevent a resurgence of the extremist group that once controlled large swaths of Syrian and Iraqi territory.

Shanahan is a former Boeing executive who's been the interim Pentagon chief since Jan. 1, when Defense Secretary Jim Mattis left.

President Donald Trump hasn't said whether he'll nominate Shanahan for the Cabinet post.