WASHINGTON — The Pentagon has stepped up airstrikes and special operations raids in Afghanistan to the highest levels since 2014 in what Defense Department officials described as a coordinated series of attacks on Taliban leaders and fighters.

The surge, which began during the fall, is intended to give American negotiators leverage in peace talks with the Taliban after President Trump said he would begin withdrawing troops and wind down the nearly 18-year war.

The campaign appears to have registered with the militants: During negotiations, the Taliban complained bitterly about the torrent of airstrikes, according to two senior Afghan officials who have spoken to Zalmay Khalilzad, the American special envoy who is leading the talks.

“They say they have learned from their mistakes of the past,” Mr. Khalilzad said in a speech on Friday in Washington. He said the Taliban did not want to be “a pariah state” and had told him that they did not see a military solution to the conflict.