Russian President Vladimir Putin says it's "too early" to release Ukrainian sailors and naval vessels seized in the Sea of Azov, and has accused the government of Ukraine of provoking an incident to distract from their own domestic problems.

In statements to reporters following the G-20 summit in Buenos Aires, Putin covered a wide array of topics, including oil production and a possible detente with the UK in the hopes that the nations can overcome differences and normalize relations.

On the topic of Ukraine, however, Putin took a harder stance over Moscow's refusal to release the 24 captured sailors - an international incident which resulted in US President Trump canceling a meeting with Putin amid the uproar (the two instead had a brief side-chat).

Russia detained the two artillery ships and a tugboat after forcing them to stop at gunpoint after what Moscow described as "dangerous maneuvering" in the waters near the Kerch Strait.

Putin said that it was necessary to hold the sailors captive while a legal case was constructed that would show that the three Ukrainian naval vessels were in violation of Russian territorial waters - and that the ship's logs would reveal their attempt to cross the Kerch strait from the Black Sea into the Sea of Azov, which is enclosed by Russia, the Crimean peninsula and mainland Ukraine.

When asked if the Kremlin might be willing to exchange the sailors for Russians detained by Ukraine, Putin replied: "We are not considering a swap and Ukraine did not raise this issue, and it’s too early to talk about that. They are still being investigated. We need to establish the fact that this was a provocation by the Ukrainian government and we need to put all these things on paper."

Putin also suggested that the incident was part of a wider pattern of provocation by Kiev.

"The current Ukrainian leadership is not interested in resolving this at all," said the Russian leader. "As long as they stay in power, war will continue. Why? Because when you have provocations, such hostilities like what just happened in the Black Sea … you can always use war to justify your economic failures."

Last week, Russia's FSB security service released a video of three men admitting they provoked the incident with Russia.

One of the crew members, who is identified by Russian media as Andrey Drach, an agent with the Main Directorate of Military Counterintelligence of Ukraine’s Security Service, said Russia’s Coast Guard repeatedly warned the Ukrainian ships against entering Russian water.

"On the way to Mariupol through the Kerch Strait we reached the territorial waters of the Russian Federation where the Border Service of the Russian Federation warned us that that we violated the legislation of the Russian Federation. They told us repeatedly to leave the territorial waters of the Russian Federation."

A second sailor confirmed Drach's statement. He was identified as Sergey Tsybizov, a sailor aboard the navy ship Nikopol:

"We sailed further on 'Nikopol' and Russian vessels contacted us and requested us to stop and reverse."

And in a third released by the FSB, a man identified as Vladimir Lesovoy, a captain of the third rank, said that the sailors were aware that their actions were "provocative in nature." Ukraine has since declared martial law as tensions continue to escalate between the two nations.

Putin gave conflicting accounts of the Kerch incident. He first alleged that the Ukrainian boats, two small gunboats and a tugboat, had been trying to cross the strait in secret, when they clashed with the Russian coastguard. The Ukrainian tugboat was rammed by Russian vessels, and one of the gunboats was fired on, sustaining damage in the hull and the bridge. Moscow said the clash took place inside Russia’s territorial waters, which extend 12 miles (20km) from the coastline, which Ukraine denies. Kiev says its vessels notified the Russian maritime authorities of their intention of going through the strait and that the Russians opened fire on its vessels after they had turned around and were heading away from the strait into the open wars of the Black Sea. In his remarks in Buenos Aires, Putin appeared to confirm some of Kiev’s claims, conceding that the Ukrainian and Russian vessels had been in contact with each other before the incident, and that the Ukrainians had refused to use a Russian pilot to help them navigate the narrow strait. The Ukrainians reject Russian insistence that they use a Russian pilot, saying it is not required by a 2003 agreement on sharing the waterway, and is a recently imposed means of controlling Ukrainian access. -Guardian

Putin, meanwhile, said that the Russian coast guard "told them to stop and they did not respond."

"They started running away, so that’s it," he said. "The border guards acted in accordance with the orders they were given. Any border guards of any country would do that if their border was violated."