New Delhi, Dec. 20 -- Secretary of State Marco Rubio was hopeful but clear about the challenges facing the Trump administration's Russia-Ukraine and Israel-Hamas peace efforts and defended increasing U.S. military pressure on Venezuela during a marathon end-of-year news conference Friday.

In a freewheeling exchange with reporters running more than two hours, Rubio offered no predictions for timing or success on any of those three issues. He also said he was proud of President Donald Trump's radical overhaul in foreign assistance and that the administration was working to reach a humanitarian ceasefire in Sudan in time for the new year.

Rubio's rare and lengthy appearance in the State Department briefing room came as key meetings on Gaza...