Defense Secretary Jim Mattis signaled Tuesday the U.S.-led coalition's continued commitment to the fight in Afghanistan, amid persistent questions about a possible withdrawal and a spate of suicide bombings.

Mattis said the U.S. will stand by the Afghan people and the government, and added that "the NATO mission will continue" in a campaign to push the Taliban to the peace table.

Two Islamic State suicide bombers hit Kabul on Monday, killing 25 people, including nine journalists who had rushed to the scene of the first attack. It was the latest in a string of large-scale bombings in the capital and across the country this year.

Asked about the attacks, Mattis said the U.S. knew there would be tough fighting this year. He spoke at the start of a meeting with Macedonia Defense Minister Radmila Shekerinska.

"We anticipated and are doing our best and have been successful at blocking many of these attacks on innocent people but unfortunately once in a while they get through because any terrorist organization that realizes it can't win by ballots and turns to bombs, this is simply what they do," Mattis said.

A new report from an independent auditing agency released Tuesday painted a bleak picture of progress in the war, which has been raging for more than 16 years. The report by the Special Inspector General for Afghanistan Reconstruction, or SIGAR, said that as of the end of January, 14.5 percent of the country's districts are under the control or influence of insurgents, the highest level recorded in recent years. It also said that the insurgents gained control over a larger portion of the population — from 9 percent in August 2016 to 12 percent in January.

SIGAR added that the size of the Afghan security forces has sharply declined over the past year. It said the force, including national police and army troops, totals a bit more than 296,000, or almost 36,000 fewer than a year ago.

Pentagon officials, however, have said that the Afghan forces have been improving in recent months, as the U.S. beefs up training and advising local forces in the country. Hundreds of new advisers deployed to Afghanistan after the closing date of the SIGAR report.

Mattis added that the Taliban will likely continue to target election and polling locations, as the nation continues to prepare for voting later this summer. He said both IS and the Taliban are trying to destabilize the country.

In remarks to reporters on Monday, the Pentagon chief flatly rejected suggestions that the White House wants to withdraw from Afghanistan.

"We're there to do a job," he said. "We're not there to stay forever, but the job comes first."

Sen. Rand Paul, R-Ky., said last week that he changed his mind and voted in favor of Mike Pompeo for secretary of state after having conversations with President Donald Trump. He said he received reassurances that Pompeo agrees with the president that the Iraq war was a "mistake" and that it is time for U.S. troops to leave Afghanistan.