Russia-Ukraine updates: Putin suspends key US-Russia nuclear treaty in speech denouncing West

Russia's eroding situation could lead Russian President Vladimir Putin to "more nuclear saber-rattling," U.S. Defense Secretary Lloyd Austin warned Saturday.

"The ripples of Russia’s invasion has traveled far beyond Europe. Beijing, like Moscow, seeks a world where autocrats can stamp out the flame of freedom," Austin said while addressing the Halifax International Security Forum.

Austin said the deadly explosion in Poland this week was the result of the "recklessness of Putin’s war of choice."

"Russia’s invasion offers a preview of a possible world of tyranny and turmoil that none of us would want to live in. And it’s an invitation to an increasingly insecure world haunted by the shadow of nuclear proliferation," Austin said.

He went on, "Putin’s fellow autocrats are watching and they could well conclude that getting nuclear weapons would give them a hunting license of their own. And that could drive a dangerous spiral of nuclear proliferation."

-ABC News' Matt Seyler

An investigation into the cause of a leak from the Nord Stream pipelines in the Baltic Sea revealed "extensive damage" and several "foreign items," some with detectable "explosive residue," the Swedish Security Service and a prosecutor said Friday.

"The advanced analysis work is still in progress – the aim is to draw more definitive conclusions about the Nord Stream incidents. The investigation is extensive and complex and will eventually show whether anyone can be suspected of, and later prosecuted for this," prosecutor Mats Ljungqvist and the Swedish Security Service said in a statement.

Several blasts near the Nord Stream 1 and Nord Stream 2 gas pipelines on Sept. 26 caused leaks. Officials are still investigating the cause of the blasts. Major pipelines which supply natural gas from Russia to Europe, were shut off in September. While they were not in use at the time of the blast, the pipelines were filled with natural gas.

-ABC News' Will Gretsky

A Russian missile strike on the Ukrainian city of Dnipro has left 23 people injured, 15 of whom are in hospital. One person is in grave condition, according to Valentyn Reznichenko, the governor of the Dnipropetrovsk Oblast.

Local officials earlier said the strike had left at least 14 people dead.

Air raid sirens went off in several Ukrainian cities including Odessa and Zaporizhzhia. Officials said four missiles were shot down in Kyiv.

-ABC News' Will Gretsky, Joe Simonetti and James Longman

Polish authorities have granted Ukrainian investigators access to site of the missile explosion, as an investigation into the origin of the missile continues, according to Jakub Kumoch, an aide to Polish President Andrzej Duda.

Ukrainian President Volodymyr Zelenskyy, who denies that the missile originated from Ukrainian air defense, has been requesting access to the site.

-ABC News' Will Gretsky