Ukraine's parliament approved the introduction of martial law on Monday in the border regions of the country for 30 days, after Russian Federation seized three of Kiev's ships in a confrontation at sea. "First it was Crimea, then eastern Ukraine, now he wants the Sea of Azov", Mr Poreshenko said.
According to him, the United States fully supports Ukraine's sovereignty, independence, and territorial integrity within its internationally recognized borders, extending to its territorial waters.
"The Montreux Convention clearly states: if a conflict occurs between two countries, and one of them is the aggressor, then the Bosphorus automatically closes for ships flying its flag", said Voronchenko told the Kyiv-based Interfax-Ukraine news agency during the 2nd global conference on maritime security in in Kyiv on Thursday.
Porshenko has claimed that Putin wants "nothing less" than to occupy the Sea of Azov.
"Several allies conduct North Atlantic Treaty Organisation air policing in the region, and allies also conduct regular reconnaissance flights over the Black Sea".
A column of what appeared to be anti-ship missile systems was spotted on a highway headed toward the Crimean city of Kerch on Tuesday, the Russian state-funded television network RT reported.
South African World Cup victor Naka Drotske shot in Pretoria
Naka and Os are two of our legendary players, coaches and friends and we keep them in our thoughts and prayers. Drotske won 26 caps for South Africa between 1993 and 1999 and also played for London Irish from 2001-2003.
German Chancellor Angela Merkel said she plans to press Russian President Vladimir Putin at this weekend's G20 summit in Argentina to urge the release of the ships and crews, but added that, "we can only resolve this in talks with one another because there is no military solution to all of these conflicts".
Adrian Karatnycky of the Atlantic Council urges us to build up USA naval forces in the Black Sea, send anti-aircraft and anti-ship missiles to Ukraine, ratchet up sanctions on Russia, threaten to expel her from the SWIFT system of worldwide bank transactions, and pressure Europe to cancel the Russians' Nord Stream 2 and South Stream oil pipelines into Europe.
Poroshenko's introduction of martial law has been met with criticism in Ukraine, where some lawmakers and rights campaigners have called it a threat to democracy, alleging it's an effort to help the president ahead of elections in March, which he's now expected to lose. In practical terms it could easily block the Kerch Strait as it did earlier this week by placing a merchant vessel across the channel. "We had to react after this act of aggression and that's why I have decreed martial law in some regions because we need to protect our country".
The president did not say how long the ban would last.
Mr Poroshenko has low popularity ratings.
The Kremlin said it still expected the Putin-Trump meeting to take place and played down the threat of cancellation, with foreign policy advisor Yuri Ushakov saying: "The meeting is equally needed by both sides".
After three days of debate, the European Union issued a statement expressing "utmost concern about the unsafe increase of tensions" and dismay at the "unacceptable" use of force by Russian Federation. Poland had wanted new sanctions on Moscow while Germany and France stressed the need to ease tensions.