"The object of the conference would be to assess the progress that has already been made by Ukraine and how best we in Europe and the United States might continue our joint support for the country," according to a letter of MEPs to U.S. Congress on Ukraine.

"Such a meeting would complement the celebration of the granting, in May or June of this year, of a visa-free travel to Ukrainian citizens within the EU Schengen area. It is essential that we stand strong, firm and united in defense of Ukraine, of Europe and of America," reads the letter.

As UNIAN reported earlier, according to RFE/RL correspondent in Brussels Rikard Jozwiak, it is estimated that visa liberalization for Ukraine will enter into force on June 12, 2017.

The European Parliament on December 15 adopted proposals for a visa waiver suspension mechanism. This decision is yet to be approved by the Council of the European Union.

The issue of visa liberalization for Ukraine will be put to the vote in the European Parliament immediately after the completion of the inter-institutional negotiations.