RIYADH, April 29 (Reuters) - The United States has seen "measurable progress" in the humanitarian situation in Gaza over the past few weeks, U.S. secretary of state Antony Blinken said on Monday, but urged Israel to do more.

Speaking in Riyadh at the opening of a US-Gulf Cooperation Council meeting, Blinken said the most effective way to alleviate the humanitarian crisis in Gaza was to achieve a ceasefire. He also said Washington continued efforts to prevent the Gaza war from expanding. (Reporting by Humeyra Pamuk; Editing by Michael Georgy)