Syrian President Bashar al-Assad visited government troops on the front line with jihadists in Idlib Tuesday, his first visit to the northwestern province since the start of the conflict.

While President Donald Trump insists he's bringing home Americans from "endless wars" in the Mideast, his Pentagon chief says all U.S. troops leaving Syria will go to western Iraq and the American military will continue operations against the Islamic State group.

They aren't coming home and the United States isn't leaving the turbulent Middle East, according to current plans outlined by U.S. Defense Secretary Mark Esper before he arrived in Afghanistan on Sunday. The fight in Syria against IS, once spearheaded by American allied Syrian Kurds who have been cast aside by Trump, will be undertaken by U.S. forces, possibly from neighboring Iraq.

The Syrian army deployed alongside Kurdish forces on the front line in northern Syria Wednesday but their newfound cooperation saw no let-up in the week-old Turkish invasion, a monitor said.

Canada on Tuesday announced it had temporarily suspended "new export permits" to Turkey, particularly of military equipment, in response to Ankara's offensive into northern Syria.

The United States wants to maintain support for the Kurdish-led Syrian Democratic Forces (SDF) in their fight against Islamic State militants despite US troops withdrawing from northern Syria, a Pentagon official said Tuesday. 

President Recep Tayyip Erdogan said Tuesday that Turkey's operation against Kurdish militants in northern Syria would not stop until "our objectives have been achieved".

The United States slapped sanctions on Turkey Monday as it demanded an end to the deadly incursion against Syrian Kurdish fighters, accusing its NATO partner of putting civilians at risk and allowing the release of Islamic State extremists.

EU foreign ministers on Monday voiced concern and condemnation at Turkey's assault on Kurdish forces in northern Syria, but warned their options for coordinated action across the bloc were limited.

The Syrian regime sent troops towards the Turkish border Monday to contain Ankara's deadly offensive against the Kurds, stepping in for US forces due to begin a controversial withdrawal.

NATO Secretary General Jens Stoltenberg expressed "serious concerns" on Friday about Turkey's ongoing operation against Kurdish forces in Syria and called for "restraint".