Speaking at the Munich Security Conference on Saturday afternoon, Ukrainian President Volodymr Zelensky said that Ukraine would defend its land with or without the support of partners and that NATO needs to start being honest about whether or not they want Ukraine membership.
Stressing the need for peace, he said that Crimea and occupied areas of Donbass would be returned to Ukraine only by peaceful means.
Complying with Russian demands is not the way to achieve peace in Europe, the Polish prime minister said on Saturday, amid rising tension surrounding the situation in Ukraine.
"It is naive to believe that fulfilling some of the demands of Russia will lead to peaceful cohabitation, peaceful coexistence," Mateusz Morawiecki said at the Munich Security Conference.
The West will need an overwhelming display of unity if it is to persuade Russian President Vladimir Putin to avoid a "catastrophic" invasion of Ukraine, British Prime Minister Boris Johnson said on Saturday.
He made the comments before visiting the Munich Security Conference, which has been dominated by the crisis over Ukraine and Western concern that Russia is poised to invade its neighbor.
"There is still a chance to avoid unnecessary bloodshed, but it will require an overwhelming display of western solidarity beyond anything we have seen in recent history," Johnson said in a written statement to media.
The three-day Munich meeting, which began on Friday, has been attended by dignitaries including US Vice President Kamala Harris and NATO Secretary-General Jens Stoltenberg.
"I'll be urging unity in the face of potential Russian aggression in Ukraine. And that unity is absolutely vital if we're going to deter what I think would be an absolutely catastrophic act of aggression by Vladimir Putin," Johnson said in a video on social media.
Johnson's office said he would deliver a similar message in his speech at the conference, and while in Munich would also meet with several European partners to discuss the response to the Ukraine crisis.
NATO Secretary-General Jens Stoltenberg said on Saturday he had sent a letter to Russian Foreign Minister Sergei Lavrov offering more talks to defuse a possible conflict in Ukraine but warned Moscow of the dangers of making impossible security demands.
Stoltenberg said he sent the letter on Thursday urging Lavrov to agree to more talks in the format of the NATO-Russia Council, which met in January to formally discuss Moscow's calls for allies to withdraw troops from eastern Europe.
He also told the Munich Security Conference that there were no signs of a Russian withdrawal from the borders of Ukraine - despite Russia's assertion this week that it had begun withdrawing troops - and that the risk of a conflict was real as Moscow's military build-up continued.
"I have invited Russia and all NATO allies to meetings in the NATO-Russia Council. And I reiterated my invitation in the letter that I sent to minister Lavrov on Thursday," he said.
"We are extremely concerned because we see that they continue to build up, they continue to prepare. And we have never in Europe seen since the end of the Cold War, such a large concentration of combat-ready troops," he said.
In a rare admission of the limits of diplomacy, Stoltenberg also told the conference that Moscow was putting forward security demands that the Kremlin knew NATO could never meet.
In a stand-off over Ukraine, Russia has sent tens of thousands of troops near the border with its neighbor while insisting it has no plans to invade. President Vladimir Putin is pressing security demands including a block on Ukraine ever joining NATO. NATO has said that, under United Nations treaties, every nation is free to choose its alliances.
"So that danger is now the combination of this massive military buildup, with the very threatening rhetoric, putting forward demands they know we cannot meet and say if we don't meet them, they will be military consequences," he said.
Speaking alongside Stoltenberg, European Commission President Ursula von der Leyen said Moscow's threats towards Ukraine could reshape the entire international system and would also cost Moscow economically.
"The world has been watching in disbelief as we face the largest build-up of troops on European soil since the darkest days of the Cold War, because the events of these days could reshape the entire international order," von der Leyen said.
Zelensky met Vice President Kamala Harris in Munich on Saturday and said his country is looking for "peace," after the United States said Russia could invade the country in the coming days.
Zelensky, who spoke briefly, also said Ukraine is looking for specific support from the United States for its army.
He also said he wanted to convene a meeting of global powers to secure new security guarantees for Ukraine because the current global system is too weak and called on members of the NATO alliance to be honest about whether they wanted Ukraine to join.
NATO relocated Ukraine staff from the capital Kyiv to Lviv in the west of the country and to Brussels for safety reasons, a NATO official said on Saturday, confirming a report by Norwegian daily VG.
"The safety of our personnel is paramount, so staff have been relocated to Lviv and Brussels. The NATO offices in Ukraine remain operational," the official said, without giving any details on the number and jobs of those moved.
NATO and allied countries were monitoring and assessing the situation very closely, according to the official, and continue to take all the necessary measures.
Lviv is in the far west of Ukraine. Many countries have moved diplomats there from Kyiv further in the east.
The European Union has delivered emergency medical equipment to Ukraine following a request from Kyiv amid an escalation of the crisis with Russia, the European Commission said on Saturday.
The request was made by Ukraine on Tuesday, amid rising fears of an imminent Russian invasion.
So far emergency aid has come from France, Romania, Slovenia, Ireland and Austria, the Commission said.
France has sent a field hospital, medicines and hundreds of tents, blankets, sleeping bags. Additional aid, including medical equipment and power generators, were deployed by the other EU countries. More help is expected in coming days.
"Following a request from the Government of Ukraine for emergency assistance due to the threat of further escalation, the European Commission is coordinating the delivery of essential supplies to support the civilian population," said an EU statement.
When the scale of an emergency overwhelms the response capabilities of a country, it can request assistance via the EU Civil Protection Mechanism, which coordinates assistance from EU and other European countries.
Poland is ready to provide Kyiv with additional defensive weapons, Prime Minister Mateusz Morawiecki said on Saturday following a rise in tensions over Ukraine's standoff with Russia.
"We are ready to provide additional supplies of defensive weapons ... weapons that are to be used to defend (Ukraine's) territory, defend cities, defend people, places where they are against the aggressions of the Russian army," Morawiecki said during a televised news conference in Munich.
Ukraine has received a planeload of machine guns, surveillance gear and rifles as part of a Canadian military assistance package, Ukrainian Defence Minister Oleksii Reznikov said on Saturday.
Ukraine has received plan loads of arms and military gear from NATO allies as the country braces for a possible military attack by Russia.
"We received military aid in the form of rifles, machine guns with optical sights, night vision & surveillance devices & military equipment. Thank you for this important & timely decision," Reznikov wrote in a tweet.
Jerusalem Post Staff contributed to this report.