"The conditions for that will be negotiated between the two parties, as it can only be, because they know the details of a negotiation that nobody else would be aware of," Trump s

The Vatican has a deep history of conflict mediation, with varying degrees of success. An effort by the pope to end the war in Ukraine would face long odds.

Without waiting for Washington, the European Union and the U.K. announced a new raft of sanctions against Russia on Tuesday, less than 24 hours after President Donald Trump and his Russian counterpart Vladimir Putin exchanged a friendly,