The US position remains unchanged - Americans continue to insist on the resignation of Bashar al-Assad as president of Syria in the long term. In the short term, the Americans require cessation of operations against militants in Aleppo, the organization of a so-called "Humanitarian corridor" and the termination of the Syrian Air flights. At the same time, they want to start a joint anti-terrorist campaign by the US and Russia.
In fact, the Americans demand that Russia provide another breather for Islamist militants and join the US war strategy. At the same time the position of the United States itself in Syria is extremely shaky. NATO member Turkey is waging a war against Syrian Kurds, who are supported by the US, the militants are being defeated in Aleppo, their success in certain sectors of the front does not negate the fact the United States is losing control over the situation in the country.
A factor that may lead to Russia agreeing to a compromise is the depletion of the Syrian government troops during the course of the war over a number of years. This is unlike the insurgents who have almost unlimited human resources (Islamists pour in from around the world). However, the combat capability of insurgents depends on foreign inflows and the drop in oil prices had a negative impact on the economies of the Gulf countries, the main sponsors of the Islamists. It is unlikely that Russia will agree to make serious concessions to the US, given the situation.
In the context of the Turkish operation in Syria, de facto being carried out independently of the United States and Russia, without connecting Turkey to the negotiating process there cannot be any viable peace strategy. This is another factor contributing to the limited effect of the Geneva talks.