Secretary of State Rex Tillerson said he sees no reason for retaliation from Russian Federation for US missile strikes on a Syrian air base.
Syrian officials have also said the strike has killed at least seven people, including children.
The U.S. air strike on a Syrian air base early on April 7 is a "positive response against the al-Assad regime's war crimes", Turkish Presidential spokesperson İbrahim Kalın has stated, calling for a no-fly zone in Syria.
"But I don't see this as enough", Erdogan says, and repeats Turkey's calls for a "terror-free zone" to be established.
Turkish Foreign Minister Mevlut Cavusoglu also said safe zones in Syria were "now more important than ever".
"If Russia wants to be absolved of responsibility for future attacks, Vladimir Putin needs to enforce commitments, to dismantle Assad's chemical weapons arsenal for good, and to get fully engaged with the United Nations peacekeeping process", he wrote.
"This regime should be ousted from leading Syria at once".
A UN-mediated peace process in Geneva has yielded few results since 2012, while the Security Council has been hamstrung by Russian Federation, a permanent member, shielding the Syrian regime from worldwide repercussions.More news: Search for More Remains where Woman's Skull Found
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Both Washington and Ankara blame the Syrian government for the poison gas attack, but Damascus has denied responsibility.
Despite its quick endorsement of the US action, Ankara has been deeply at odds with Washington in other areas of Syria policy.
The Foreign Secretary said: "Developments in Syria have changed the situation fundamentally".
The YPG is a key part of the Syrian Democratic Forces (SDF) alliance which is receiving US military support.
"My priority is now to continue contact with the United States and others in the run-up to the G7 meeting on 10-11 April - to build coordinated global support for a ceasefire on the ground and an intensified political process", Johnson said.
Erdogan has said Turkey, which hosts warplanes from the US -led coalition in its southern Incirlik airbase, would be ready to support further USA action in Syria.
Kemal Kilicdaroglu, leader of the main opposition Republican People's Party, appeared at a rally in the northern city of Trabzon.