Pence, Pompeo to lead US delegation to Turkey amid Syria offensive

"They are leaving tomorrow," Trump told reporters at the White House, a day after Pence announced the trip, without giving a timetable.

"We are asking for a ceasefire... We put the strongest sanctions that you can imagine."

Pence's office released a separate statement adding that he would "voice the United States' commitment to reach an immediate ceasefire and the conditions for a negotiated settlement."

Pence is due to meet Turkish President Recep Tayyip Erdogan on Thursday, the statement added, to reiterate Trump's commitment to "punishing economic sanctions" on Turkey until a resolution is reached.

The president's abrupt decision this month to withdraw US forces from northeast Syria left the Kurdish-led Syrian Democratic Forces (SDF) at the mercy of Turkish troops and their Syrian proxies.

The Kurds say hundreds of imprisoned relatives of militants from the Islamic State group - also known as ISIS - have escaped since Turkey launched its assault last week, although Trump suggested the SDF may have deliberately released them to gain leverage.

"The ongoing violence in the region, severely undermines the (Defeat ISIS) campaign, endangers civilians and religious minorities, and threatens the security of the entire region," the vice president's office said.

"The administration is resolved to maintain security in the region, the safety of civilians, and the continued detention of ISIS fighters."

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