WASHINGTON - President Donald Trump on Wednesday played down the crisis in Syria touched off by Turkey's incursion against U.S.-allied Kurdish forces, saying the conflict was between Turkey and Syria and that it was "fine" for Russia to help Damascus.Trump, speaking to reporters at the White House, said imposing U.S. sanctions on Turkey would be better than fighting in the region and that it was up to the countries there to work it out.South Carolina Senator Lindsey Graham (R.) responded to Trumps statements, tweeting "I hope President Trump is right in his belief that Turkeys invasion of Syria is of no concern to us, abandoning the Kurds won’t come back to haunt us, ISIS won’t reemerge, and Iran will not fill the vacuum created by this decision."He added "however, I firmly believe that if President Trump continues to make such statements this will be a disaster worse than President Obama’s decision to leave Iraq." Graham is usually a Trump loyalist, but Trump's decision to withdraw troops from Syria has driven a wedge between the two, complicating the normally supportive relationship between them.Later on Wednesday, Trump's vice president and top diplomat are scheduled to travel to Ankara to meet with Erdogan, who Trump has invited to the White House next month. U.S. Secretary of State Mike Pompeo earlier on Wednesday said the goal was to seek a ceasefire."The statements by President Trump about Turkey’s invasion being of no concern to us also completely undercut Vice President Pence and Sec. Pompeo’s ability to end the conflict," Sen. Graham added.Erdogan, speaking to reporters in the Turkish parliament earlier on Wednesday, said he was reevaluating his planned visit to Washington in November but may visit Russia.Kurdish-allied forces, backed by American troops, had been a strategic U.S. partner in the fight against Islamic State in northeastern Syria before Turkey launched an assault in the area following a phone call between Turkish President Tayyip Erdogan and Trump last week.The Kurds are "not angels," Trump said.