Afghan government 'must be involved' in US-Taliban peace talks
The Taliban view President Ashraf Ghani and his government as US-backed puppets and have refused to hold direct negotiations with Kabul.
"Ultimately, we need to get to a Taliban-Afghanistan discussion," General Joseph Votel, the head of US Central Command, told US lawmakers.
"Only they will be able to resolve the key issues involved in the dispute."
US special envoy Zalmay Khalilzad has led talks as President Donald Trump seeks to pull US troops from Afghanistan and end the years' long war against the Taliban.
"I would characterise where we are in the process as very, very early in the process," Votel said.
"Ambassador Khalilzad is attempting to create a framework by which we can move forward with discussions. That would be certainly involving the government of Afghanistan."
US Secretary of State Mike Pompeo, who "underscored the central importance" of the Kabul government in the talks, President Ashraf Ghani said.
The Taliban also met officials Moscow on Tuesday, but also Afghan politicians outside government.
The radical movement demanded a new constitution for Afghanistan while promising an "inclusive Islamic system", but are said to have made some concessions on women's rights and other issues.
While no representatives from the Kabul government were invited, some of Ghani's chief rivals - including former president Hamid Karzai - were there.