Washington, Oct 11 (IANS): Forty-nine per cent of Americans have said that the US has "mostly failed" even after being 17 years into war in Afghanistan, according to a new poll.

The poll released by the Washington-based Pew research centre also showed that about 35 per cent of respondents said it has mostly succeeded, reports Xinhua news agency.

In surveys conducted in 2014 and 2015, opinions about the mission were similarly more negative than positive, said Pew.

The centre also revealed that between 2009 and 2011, when asked whether the US will succeed or fail to achieve its goals, majorities said Washington would be successful.

Meanwhile, fewer Americans feel confident today that it was a right decision to use military force in Afghanistan.

The poll showed that 45 per cent of people said it was a right decision, down sharply from 69 per cent in 2006.

Pew also noticed that Republicans have consistently expressed more support than Democrats for the decision to use force in Afghanistan, though support has fallen in both parties over the past decade.

The US waged a "war on terror" in Afghanistan not long after the September 2001 attacks.