The United States admitted Thursday that it is no longer focused on ousting Bashar Assad as it seeks a new strategy to end Syria's civil war.

American officials have been shifting away from their former insistence that he must go for some time, but now they have made it explicit.

In New York, U.S. ambassador to the United Nations Nikki Haley condemned Assad's history of human rights abuses against his own people. But she said Washington would focus on working with powers like Turkey and Russia to seek a political settlement, rather than focusing on Assad.

"You pick and choose your battles," Haley told reporters. "And when we're looking at this, it's about changing up priorities, and our priority is no longer to sit and focus on getting Assad out."

Shortly before Haley briefed a small group of journalists, U.S. Secretary of State Rex Tillerson sent a similar signal at a news conference in Turkey.

"I think the ... longer-term status of … Assad will be decided by the Syrian people," Tillerson said, standing alongside Turkish Foreign Minister Mevlüt Çavuşoğlu.

The U.S. State Department and the White House are sending contradictory messages on Syria and should start leading and not focus exclusively on fighting Daesh, Syrian opposition member Farah al-Atassi said on Thursday.

Atassi, a member of the opposition's High Negotiations Committee, told reporters in Geneva that the United States should put pressure on Russia and see the Syrian rebels as a reliable partner against terrorism, meaning not only Daesh but also Iran-backed militias such as Hezbollah and the Iranian Revolutionary Guards.

The opposition insists that after presiding over six years of conflict in which hundreds of thousands of Syrian citizens have died, Assad can play no part in transitional arrangements being negotiated in the U.N., nor should he stand in a future election.

Under Barack Obama's administration, the U.S. made Assad's departure a key goal, but new President Donald Trump has put the accent on defeating the Daesh terrorist group.

Tillerson's reference to the Syrian people's decision reflected language long used by Assad's ally Russia, whose assistance Washington is courting.

"Our priority is to really look at how do we get things done? Who do we need to work with to really make a difference for the people in Syria," Haley said.

"We cannot necessarily focus on Assad the way the previous administration maybe did. Do we think he is a hindrance? Yes," she said. "Are we going to sit there and focus on getting him out? No."

U.S. officials sought to play down the significance of the change in tone, but experts said the switch in focus was an important admission.

Tillerson is due in Moscow next month for talks with Russian leaders, and Trump has long argued the powers should work together against Daesh.

Tillerson's trip came the day after Turkey announced the end of "Euphrates Shield," its own six-month-old military offensive in northern Syria.