WASHINGTON -- Russia said on Wednesday it still expects a meeting between President Vladimir Putin and President Donald Trump to go ahead as planned. Mr. Trump, in an interview with The Washington Post on Tuesday, said he may cancel the sit-down with Putin in Argentina following Russia's seizure of three Ukrainian naval ships last weekend.

Kremlin spokesman Dmitry Peskov told reporters on Wednesday that the meeting is on and that Russia has not received "any other information from our U.S. counterparts."

The long-simmering conflict between Russia and Ukraine burst into the open on Sunday, when Russian border guards fired on three Ukrainian vessels and seized the ships and the crew.

Get Breaking News Delivered to Your Inbox

Mr. Trump said he would be receiving a "full report" from his national security team on Russia's recent actions in eastern Ukraine and the Black Sea. He said he would decide on a course afterward.

"Maybe I won't have the meeting," he said. "Maybe I won't even have the meeting."

Mr. Trump added: "I don't like that aggression. I don't want that aggression at all."

The comments were his strongest to date in condemnation of Russia's recent actions in Ukraine, where tensions are flaring. But White House aides were still planning for the Putin meeting after Mr. Trump's comments.

U.S. condemns Russia's "unlawful conduct"

Russia says the Ukrainian vessels sparked the confrontation earlier this week by refusing to yield upon orders from Russian border forces to change their course inside Russian territorial waters (within 12 miles of Russia's coast). Putin personally reaffirmed on Wednesday his government's insistence that the Ukrainian convoy crossed into Russian territory and ignored orders to change course.

Putin said it was a deliberate "provocation" by Ukrainian President Petro Poroshenko, orchestrated to bolster his standing ahead of presidential elections next year. Putin said it was a deliberate move by Poroshenko to use as a "pretext" to implement martial law in parts of eastern Ukraine -- which was put in place on Wednesday.

Ukraine's government has insisted it was Russian border guards who first rammed into and opened fire on the three Ukrainian navy vessels as they tried to make their way from the Black Sea toward a Ukrainian port.

On Monday, U.S. Ambassador to the United Nations called on Russia to "immediately cease its unlawful conduct" in the Black Sea near Crimea during a United Nations Security Council meeting called over the incident.

"We call on Russia to respect its international obligations and not obstruct or harass Ukraine's transit in the Kerch Strait, to release the seized Ukrainian ships and crew and to de-escalate the tensions it has created," Haley told the Council, CBS News' Pamela Falk reported.

Trump to meet Chinese leader amid trade war

The meeting between President Trump and Putin is set to be just one of several high-profile foreign-policy engagements for the U.S. leader on the whirlwind two-day visit to Argentina to attend this year's summit of the world's 20 biggest economies.

Mr. Trump also is set meet with Chinese President Xi Jinping over dinner this weekend, in what may be a pivotal session to determining if and how the ongoing trade dispute between their countries can be resolved.

The White House on Tuesday warned Xi against trying to wait out Mr. Trump in the ongoing talks, suggesting the Chinese economy was not as resilient to a trade war as would be the U.S. economy.

The warning from Larry Kudlow, director of the National Economic Council, came ahead of the two leaders' high-stakes sit-down on Saturday evening. Over the last year, the two countries have levied a series of tariffs on hundreds of billions of dollars of imports from one another, with the latest round of U.S. duties set to go into force in the new year.

Kudlow warns China that Trump is "not going away"

National Security adviser John Bolton said Mr. Trump will also be meeting with German Chancellor Angela Merkel, Japanese Prime Minister Shinzo Abe, Argentine President Mauricio Macri, South Korea's Moon Jae-in, Turkish President Recep Tayyip Erdogan and Indian Prime Minister Narendra Modi.

White House spokeswoman Sarah Huckabee Sanders called the trip an opportunity for the president to cement relations with other world leaders and advance a global economic system based on "free, fair and reciprocal trade."

The Trump-Xi meeting would be the first since the two countries began hitting each other with import taxes earlier this year. The United States targeted $250 billion in Chinese products, and Beijing lashed back by slapping tariffs on $110 billion worth of U.S. goods. The two sides have been in negotiations for months, but Kudlow described them as being stalemated until just a few weeks ago.

Kudlow said the administration has been "extremely disappointed" by China's engagement in trade talks but the meeting between Mr. Trump and Xi on the sidelines of the Group of 20 summit could be a game-changer.

"Perhaps we can break through in Buenos Aires or not," he said.

Kudlow added that if the U.S. doesn't get "satisfactory" responses to its trade positions more tariffs will be imposed. He said Mr. Trump is "not going away."

"I hope they understand that," he said.

China's foreign ministry has said a recent phone conversation between Xi and Mr. Trump about trade and other issues was "extremely positive."