The United States believes that Russia carried out a test launch of an intercontinental missile on Saturday that appears to have failed, a U.S. official said.

Russia notified the U.S. ahead of the SARMAT ICBM launch, per agreements said the official.

The failed test launch would have taken place two days before President Joe Biden arrived in Ukraine's capital, Kyiv, on an unannounced trip, as he made his way to Poland to meet with NATO allies and to give a speech marking a year of war.

Ukrainian officials on Sunday publicly claimed Russia was preparing to stage large scale nuclear exercises including a launch to coincide with Biden's trip.

-ABC News' Luis Martinez and Patrick Reevell

Correction: This post initially stated the test happened on Monday when Biden was in Ukraine. It has been updated to reflect that the test actually happened on Saturday.

Russia has suspended the New START nuclear arms treaty with the United States, Russian President Vladimir Putin said.

But he emphasised that Russia was not leaving the treaty yet, only suspending its participation in its for the time-being.

He blamed the suspension on the West, saying relations had degraded and that it was impossible currently to allow American inspections of Russian strategic nuclear sites.

Putin's decision was announced on Tuesday as he gave an annual state-of-the-union speech in Moscow, days ahead of the one-year anniversary of the invasion into Ukraine.

He also accused the United States of considering restarting nuclear bomb tests and threatened that Russia would hold them too if that happened.

That will be interpreted as a veiled threat in relation to the war in Ukraine -- experts have feared Russia might conduct a nuclear bomb test to intimidate Kyiv and its Western allies. Putin ordered Russia’s military to prepare the possibility to hold a test.

“Some actors in Washington are thinking about testing nuclear weapons,” he said. “The defense ministry and RosAtom must prepare also to conduct nuclear tests in case of necessity. But Russia will not conduct it first.”

-ABC News' Patrick Reevell

Russian President Vladimir Putin on Tuesday opened his state of the union speech in Moscow with familiar touchstones, including ridding the world of Nazism and liberating Ukraine's Donbas region.

He said of his Ukrainian invasion that the "historic events will determine the future of our country ... each of us is bound by a huge responsibility."

And he said he sought an "open dialogue" with the West, but also blamed Western countries and Ukraine's leaders for holding the country's people "hostage."

"The United States and NATO have been rapidly deploying their bases and biolabs at the borders of our country," he said.

He said Russia tried to settle the conflict in the Donbas region by peaceful means, adding that the West's commitment to peace turned out to be "fraud" and a "cruel lie."

Putin said they were open to dialogue with the West and were open to an equal system of security, but "in response we were getting dishonest answers" and specific actions to expand NATO and deploy new anti-missile systems in Europe. He said that "the whole planet is dotted" with U.S. bases.

-ABC News' Joe Simonetti

The Pentagon announced a new presidential drawdown of security aid for Ukraine valued at up to $460 million on Monday.

This package will include four Bradley Infantry Fire Support Team vehicles, HIMARS ammunition, artillery and mortar rounds, air surveillance radars and more.

President Joe Biden hinted at the new supplies in a press conference from Kyiv on Monday, also saying he would be announcing new sanctions "against elites and companies that are trying to evade sanctions and backfill Russia's war machine" later this week.

-ABC News' Matt Seyler

The nuclear watchdog of the United Nations is calling for the immediate establishment of a "nuclear safety and security protection zone" around the Russian-occupied Zaporizhzhia nuclear power plant in southeastern Ukraine.

The recommendation, among several others, was made in a second report released Tuesday by the International Atomic Energy Agency, which deployed an expert mission to the besieged plant last week.

"The IAEA recommends that shelling on site and in its vicinity should be stopped immediately to avoid any further damages to the plant and associated facilities, for the safety of the operating staff and to maintain the physical integrity to support safe and secure operation," the agency wrote in the report. "This requires agreement by all relevant parties to the establishment of a nuclear safety and security protection zone around the ZNPP."

The Zaporizhzhia nuclear power plant is the largest in Ukraine and all of Europe. Invading Russian forces overran the site and the surrounding town of Enerhodar in early March. The Ukrainian workers have been left in place to keep the plant operating, as it supplies electricity across the war-torn country, but the site is now on the front line between Russian-occupied and Ukrainian-controlled territory. Moscow and Kyiv have traded blame for shelling at or near the plant in recent days and weeks, fueling fears that the conflict could spark a radiation disaster.

The IAEA said it aims to maintain a "continued presence" at the plant to "help further improve and deepen the understanding of the situation."

"While the ongoing shelling has not yet triggered a nuclear emergency, it continues to represent a constant threat to nuclear safety and security with potential impact on critical safety functions that may lead to radiological consequences with great safety significance," the agency wrote in the latest report.