The lack of progress in the negotiations is angering Trump

US President Donald Trump said on Sunday that Ukrainian President Volodymyr Zelensky is trying to abandon a crucial agreement on underground resources, while Russian President Vladimir Putin is angering him with statements about Zelensky's legitimacy. Trump urged both sides to sit down at the negotiating table by threatening them with problems.

“He [Zelensky] is trying to back out of the agreement on rare metals, and if he continues down that path, then problems, big, very big problems will arise,” Trump said to reporters aboard his plane.

Trump also added that Zelensky “wants to be a NATO member, but he will never be a member of NATO, he understands that.”

His threats to Zelensky came after a harsh criticism directed at Putin. In an interview with NBC News, Trump said he was “very angry” after Putin last week again questioned Zelensky's legitimacy and proposed to introduce temporary governance in Ukraine under the auspices of the UN.

“In general, it is possible to discuss the possibility of introducing temporary governance in Ukraine under the auspices of the UN with the US, European countries, our partners, and friends. To hold democratic elections,” Putin said during a conversation with sailors from the nuclear submarine "Arkhangelsk."

In response, Trump said on Sunday that if Moscow feels it is obstructing his efforts to stop the war in Ukraine, it will impose “secondary tariffs” of 25 to 50 percent on buyers of Russian oil, Reuters reported.

“I can say that I was very angry when... Putin got carried away with the issue of Zelensky's legitimacy, I was very angry because it is not in line with the goal,” said the US president. “[In Ukraine] having a new leadership means that there will be no agreement for a long time,” he added.

“If we cannot agree with Russia on stopping the bloodshed in Ukraine and I consider it Russia's fault... I want to impose secondary tariffs on oil, all oil coming from Russia,” Trump said.

Trump also stated that he would set a deadline for Russia to agree to stop the shelling in Ukraine.

“This is a psychological deadline. If I find that they are dragging their feet, that does not please me,” The Hill quoted Trump as saying.

According to Reuters, Trump's sharp remarks about Putin reflect his frustration over the lack of effort to reach an agreement to stop the shelling.

Since taking office in January, Trump has taken a conciliatory stance towards Russia but has also threatened Moscow with new sanctions several times.

Earlier last week, consultations between Russia and the US took place in Saudi Arabia, resulting in similar statements from Moscow and Washington about the need to ensure safe shipping in the Black Sea.

At the same time, the Kremlin demanded the lifting of sanctions imposed on the export of Russian food and fertilizers. Kyiv opposed the lifting of the sanctions. This issue remains open.

According to a Reuters reporter from aboard the presidential plane, Trump, who threatened “secondary sanctions,” later added: “I think we are achieving step-by-step growth.” He also mentioned that he might introduce new trade measures within a month.

Kremlin spokesman Dmitry Peskov commented on reports that Trump was “angry” with Putin.

“Some of the statements you mentioned have been reworked. This is not a quote in quotation marks,” Peskov was quoted by Interfax as saying.

He also added that Moscow is “continuing to work with the American side.”

“We are continuing to work on restoring our bilateral relations, which suffered greatly during the previous administration. We are also working on implementing some ideas related to resolving the Ukraine issue. Work is ongoing, and there are no specific things we need to inform you about at this time. This is a process that will take some time,” Peskov said.

Spending the weekend at his estate in Palm Beach, Florida, Trump told an NBC News reporter that he plans to talk to Putin this week. It is known that the two politicians have communicated by phone twice in recent months, but Peskov did not rule out that there have been more such contacts.

The White House has not clarified when Trump might speak with Putin or whether the US president will talk to Zelensky or not.

In one of his comments, Trump, who called for new elections in Ukraine and referred to Zelensky as a “dictator without elections,” has repeatedly emphasized that he has a good relationship with Putin.

Trump's next sharp remarks came after an unexpected round of golf with Finnish President Alexander Stubb, who visited Florida on Saturday.

The next day, the Finnish president arrived in London and told The Guardian in an interview that Trump’s “patience is wearing thin” due to Putin dragging his feet on the issue of stopping the shelling in Ukraine.

According to Stubb's office, he told Trump that a deadline should be set for stopping the shelling between Russia and Ukraine. The Finnish president suggested April 20 as the date, as it will mark three months since Trump took office.

Trump's administration is urging Kyiv to accept the agreement on natural resources. Last week, media reported that the US presented an updated draft agreement to Kyiv, which envisions almost complete control over all mineral deposits in Ukraine without security guarantees for Kyiv.

Zelensky confirmed that Ukraine received the document. At a press conference in Paris on Thursday, he expressed regret that the terms of the agreement on underground resources are constantly changing.

The new text of the agreement has not been officially announced, but Ukrainian politicians and media, as well as leading Western publications, are analyzing it based on texts obtained from their sources.

Overall assessments – shock-negative assessments – are mostly consistent. One of the main provisions of the agreement is that Ukraine must recognize the assistance previously provided by the US as a debt, BBC's Ukrainian service reports.

“I would not want there to be a sentiment in the US that Ukraine is completely against it. We have always shown our positive signals,” Zelensky said.

William Reinsch, a former senior official at the US Department of Commerce and now working at the Center for Strategic and International Studies, told Reuters that Trump's chaotic threats regarding the imposition of economic sanctions leave many questions unanswered, including how American officials can monitor and prove which countries are buying Russian oil.

On Sunday, Trump laid the groundwork for imposing a 25 percent tariff on any country buying oil or gas from Venezuela. His interview with NBC allows for speculation that similar actions could be taken against countries buying oil from Russia, which could hit China and India hard, Reuters comments.