The Trump administration on Monday called on Turkey for “an immediate ceasefire” as it imposed sanctions on Ankara over its military incursion into Syria. US Vice President Mike Pence said he would lead a delegation to Turkey at President Donald Trump’s request to try to stop the military advance. Mr Pence said Mr Trump spoke with Turkey’s President Recep Tayyip Erdogan earlier in the day. The penalties will raise steel tariffs on Turkey to 50 per cent again, the level before a reduction in May, and the US will halt negotiations over a $100 billion trade pact, Mr Trump said. The sanctions target the Ministry of National Defence and the Ministry of Energy and Natural Resources, as well as Hulusi Akar, Minister of National Defence; Fatih Donmez, Minister of Energy and Natural resources; and the Interior Minister Suleyman Soylu. Mr Trump signed an executive order imposing the sanctions on Friday House Speaker Nancy Pelosi has been working with Republican Senator Lindsey Graham to pass legislation that would put harsh restrictions on the country. Mr Trump wrote on Twitter on Monday that he was "fully prepared to swiftly destroy Turkey’s economy if Turkish leaders continue down this dangerous and destructive path". The White House warned Turkey that “indiscriminate targeting of civilians, destruction of civilian infrastructure and targeting of ethnic or religious minorities is unacceptable". The White House also warned about the return of refugees, of which Turkey hosts about 3.6 million, to the "safe zone" Ankara wants to establish in north-east Syria. “The return of refugees must be conducted in a safe, voluntary and dignified manner,” it said. Mr Trump said: “I have been perfectly clear with President Erdogan, Turkey’s action is precipitating a humanitarian crisis and setting conditions for possible war crimes. “Unfortunately, Turkey does not appear to be mitigating the humanitarian effects of its invasion.” The US president repeated his decision to withdraw from Syria but said “a small footprint” of American forces would stay at At Tanf garrison in southern Syria to “continue to disrupt remnants of ISIS”. The Tanf base is also considered to be a crucial location for countering Iran. Mr Trump is still due to receive Mr Erdogan in Washington on November 13.