The success of an apparent agreement between Ukraine and Russia to pause naval and energy infrastructure attacks will depend on Moscow, Zelenskyy said.

NATO Secretary-General Mark Rutte has warned Russia that the alliance would always stand by Poland or any other ally and that its reaction to an attack would be “devastating.”

Month after month, Ukraine has increased the size and scope of its drone assaults within Russia despite the war's strategic pressures.

Russia and Ukraine also agreed to "develop measures to implement the agreement to ban strikes against energy facilities in Russia and Ukraine," the White House said.

Russia and Ukraine also agreed to "develop measures to implement the agreement to ban strikes against energy facilities in Russia and Ukraine," the White House said. ABC News’ Patrick Reevell reports.

American and Russian negotiators met again in Saudi Arabia on Monday as the White House continues its push for a ceasefire and eventual peace deal in Ukraine.

ABC News’ Patrick Reevell reports on Monday's talks, which follow discussions between American and Ukrainian negotiators.

Austrian authorities say they uncovered a Russian-steered campaign aimed at spreading disinformation about Ukraine following the detention in December of a Bulgarian woman accused of spying for Russia

Ukraine and Russia exchanged strikes through the night on Saturday, despite last week's apparent progress toward a United States-brokered partial ceasefire.

Cross-border drone attacks killed civilians in both Ukraine and Russia overnight into Sunday, according to local officials.

Ukrainian officials say Russian drones have struck the city of Zaporizhzhia, killing three people and wounding 12

Ukrainian authorities reported airstrikes in several regions of the country, including a drone attack on a hospital in the northeastern city of Sumy.

Russian authorities reported a "massive" Ukrainian drone attack on the Engels airbase in Saratov Oblast overnight.

U.S. Special Envoy for Ukraine and Russia Keith Kellogg addressed President Donald Trump's efforts to end the ongoing war between Ukraine and Russia.

Russian authorities reported a "massive" Ukrainian drone attack on the Engels airbase in Saratov Oblast overnight. ABC News’ Marcus Moore reports.

President Donald Trump spoke with Ukrainian President Volodymyr Zelenskyy on Wednesday as talks continue to try to end the Russia-Ukraine war.

President Donald Trump spoke with Ukrainian President Volodymyr Zelenskyy on Wednesday as talks continue to try to end the Russia-Ukraine war.

A White House readout of the call said Vladimir Putin supports President Donald Trump's idea for a mutual pause on energy infrastructure attacks, but did not agree to a 30-day ceasefire.

President Volodymyr Zelenskyy said overnight missile and drone attacks launched by Russia showed that Moscow's claimed support for a ceasefire in Ukraine is not "real."

President Donald Trump held a high-stakes call with Russia's Vladimir Putin on Tuesday as he tries to win his approval of a 30-day ceasefire with Ukraine.

In a phone call, Russian President Vladimir Putin committed to limiting Russian attacks on Ukrainian energy assets. Still, he declined to agree to a broader 30-day ceasefire as sought by Donald Trump.

ABC News’ Stephanie Ramos spoke with Steven Pifer, a former US ambassador to Ukraine, on Pres. Trump and Vladimir Putin’s two-hour conversation that ended in Putin rejecting a 30-day ceasefire plan.

Ukrainian President Volodymyr Zelenskyy, in a press conference following Tuesday's developments, said he had "skepticism" but that "if there is a partial ceasefire, this is a positive result."

President Donald Trump held a high-stakes call with Russia's Vladimir Putin on Tuesday as he tries to win his approval of a 30-day ceasefire with Ukraine.

This will be the first time President Donald Trump and President Vladimir Putin are known to have spoken since Ukraine agreed to the U.S.-proposed 30-day ceasefire plan.

Presidents Donald Trump and Vladimir Putin are expected to speak on Tuesday as the White House continues its campaign for a ceasefire and eventual peace deal.

President Donald Trump and Vladimir Putin have a phone call scheduled for Tuesday. Trump aims to end the war in Ukraine after the country has agreed to the U.S.-proposed ceasefire.

President Donald Trump plans to speak on Tuesday with Russian President Vladimir Putin amid the U.S. president’s efforts to end Russia’s war in Ukraine.

Ukrainian President Volodymyr Zelenskyy accused Russian President Vladimir Putin of "prolonging the war" and "ignoring" U.S.-led efforts to agree a ceasefire.

President Donald Trump and Russian President Vladimir Putin are expected to speak this week as the U.S. tries to broker a ceasefire in the Russia-Ukraine war, according to Trump special envoy Steve Witkoff

Amid the U.S. push for a ceasefire, Russia claims it has surrounded Ukrainian forces and recaptured territory in the Kursk region.

The developments come a day after ceasefire talks between the U.S. and Russia in Moscow.

Several Ukrainian drones were intercepted and destroyed over Moscow and the Moscow region overnight, with some coming as close as two miles away from the Kremlin.

Representatives of China, Russia and Iran called for an end to U.S. sanctions on Iran over its rapidly advancing nuclear program and a restart to multinational talks on the issue

President Donald Trump, meeting with NATO Secretary General Mark Rutte in the Oval Office, was asked what kind of agreement he hopes special envoy Steve Witkoff secures while in Russia.

President Donald Trump's Middle East envoy, Steve Witkoff, landed in Moscow on Thursday morning for discussions on a proposed 30-day ceasefire in Ukraine.

President Vladimir Putin raised questions regarding a 30-day ceasefire during a press briefing in Moscow on Thursday. ABC News' Marcus Moore reports.

U.S. special envoy Steve Witkoff is in Moscow to try and convince President Vladimir Putin to sign up to the 30-day ceasefire proposal already agreed to by Ukraine.

The prospect for a ceasefire between Russia and Ukraine "is in Moscow's hands," a top aide to Ukrainian President Volodymyr Zelenskyy said following talks with the U.S.

"I've gotten some positive messages, but a positive message means nothing," Trump said as he faced questions on what happens next with the Ukraine war ceasefire.

Trump said U.S. representatives are "going to Russia right now as we speak” to help broker a 30-day ceasefire, a proposal that the Ukrainians agreed to during peace talks in Saudi Arabia this week.

ABC News’ Patrick Reevell and contributor Darrell Blocker, a former CIA agent, discuss the prospects for a ceasefire between Russia and Ukraine.

Following talks in Saudi Arabia, the United States and Ukraine called for a 30-day ceasefire, pending Russia's acceptance.

Secretary of State Marco Rubio, who led the U.S. delegation in Jeddah, said the ceasefire proposal will be delivered to Russia "directly through multiple channels."

U.S. and Ukrainian officials met in Jeddah, Saudi Arabia, for major talks on Tuesday with the goal of charting a course toward ending Russia's three-year-old war.

Russia's Defense Ministry said its forces shot down 343 Ukrainian drones overnight, in what appeared to be Kyiv's largest ever cross-border aerial attack.

ABC News’ James Longman reports on what Russian officials are calling the largest attack ever by Ukraine on Russia since the war began.

Ukraine seized parts of the Russian territory last year.

Secretary of State Marco Rubio landed in Saudi Arabia on Monday ahead of high-stakes talks with Ukrainian officials on ending Russia's brutal invasion.

Secretary of State Marco Rubio landed in Saudi Arabia on Monday ahead of high-stakes talks with Ukrainian officials on ending Russia's brutal invasion.