The Monday talks in the Saudi capital, Riyadh, come a day after negotiations between U.S. and Ukrainian delegations in the city.

Kiev and Moscow have already agreed in principle to halt strikes on energy infrastructure for a month. That came after U.S. President Donald Trump spoke with his counterparts from Russia and Ukraine, Vladimir Putin and Volodymyr Zelensky, last week.

The U.S. is now expected to help finalize details and has expressed optimism over the outcome of the Riyadh negotiations.

“The ultimate goal is a 30-day ceasefire, during which time we discuss a permanent ceasefire. We’re not far away from that,” the U.S. special envoy Steve Witkoff said at the weekend, according to The Guardian.

The U.S. in the meantime seeks to negotiate separate measures for a maritime ceasefire in the Black Sea to ensure safe navigation.

The Riyadh negotiations are part of efforts by President Trump to resolve the three-year-old conflict between Russia and Ukraine. Despite that, gaps remain between Washington and Europe that has remained skeptical about Trump’s efforts over what it sees as his pro-Russia stance. 

Russia has said any ceasefire deal with Ukraine should address Moscow’s security concerns. It says Ukraine must formally abandon its ambition to join the western military alliance, NATO, which Russia says its expansion eastward poses a threat to its security.

Russian and American officials met for the first time in Saudi Arabia on February 18 for the Ukraine ceasefire talks.