By Idrees Ali WASHINGTON (Reuters) – The United States has restarted on-site inspections in Ukraine to help keep track of the billions of dollars of weapons being provided to Kyiv, a senior U.S. official said on Monday. Moving large amounts of weaponry into the largest conflict in Europe since World War Two carries with it risks that some could fall into the wrong hands. But U.S. officials have said that it has been a risk worth taking in providing about $18 billion in weapons since Russia’s invasion of Ukraine in February. A senior U.S. defense official, speaking on the condition of anonymity…