"The United States has again joined the talks today in Doha. The discussions will focus on reducing violence, which leads to internal Afghan negotiations and a ceasefire," the source told Reuters.
The United States and the Taliban were about to sign an agreement in September, under which Washington would begin withdrawing thousands of soldiers in exchange for security guarantees.
But in the same month, Trump announced that the talks had become "dead" and canceled an invitation to insurgents for secret talks at Camp David in the wake of the killing of a US soldier in Afghanistan.
The United States currently has about 14,000 troops in Afghanistan. It was supposed to withdraw 5,400 soldiers, from 5 bases within 20 weeks, under the proposed peace agreement.
During a surprise visit to a US military base in Afghanistan last week, Trump said the Taliban "want to reach an agreement."
American diplomats had revealed earlier that Washington had discovered that the Qatari interests in hosting negotiations with the Taliban were totally incompatible with the American interest. Which prompted the American President to cancel the idea of negotiating from its origin with a terrorist movement.
Qatar supports organizations classified under the terrorism regulations, including the Taliban, Jabhet al-Nusra, and other terrorist groups in Syria.