Ukraine's Prime Minister Arseniy Yatsenyuk, Georgia's Prime Minister Irakli Garibashvili, and Moldovan Prime Minister Iurie Leanca are due in the German capital later today.
The talks are expected to focus specifically on the outcome of last weekend's presidential election, which was won in the first round by billionaire oligarch Petro Poroshenko.
In a telephone conversation yesterday, Merkel congratulated Poroshenko on his election and said it was now time to "continue the path of internal reconciliation."
In a statement, Merkel in particular paid tribute to people who turned out to vote in the rebel-held east of the country "despite harassment and intimidation," saying it was a "sign of hope."
Poroschenko/Klitschko-interview in @BILD now without paywall #Ukraine http://t.co/bNeO8RTuMh
— Paul Ronzheimer (@ronzheimer) May 28, 2014
The commission said in a statement today that "Ukraine has put in place the necessary legislative, policy and institutional framework and meets the first-phase requirements" for EU visa-free travel.
The commission said that this clears the way for launching the second phase where the EU will check to see, for example, whether laws on issuing secure documents or controlling illegal immigration, are in place.
Commission president Jose Manual Barroso said, "While important work still lies ahead, this is a very concrete sign to the Ukrainian authorities and citizens that with perseverance the benefits of a closer association with the EU are real and tangible to all."
Improved travel ties are part of EU efforts to solidify political and economic ties with Ukraine.
EC approves launch of second phase of visa liberalization process with #Ukraine http://t.co/nkZtrhXBFK pic.twitter.com/J1AmHmk1vx
— Kyiv Post (@KyivPost) May 27, 2014
The danish government confirms that the missing OSCE observers in #Donetsk are detained by armed separatists. @CBCNews
— J-Francois Belanger (@belangerjf) May 27, 2014
Very nice by @kgorchinskaya: Election day pictures and what they mean http://t.co/mE3XkgOaIR
— Glenn Kates (@gkates) May 27, 2014
#Donetsk airport unlikely to open anytime soon. Footage shows terminal destroyed after fierce gun battle yesterday http://t.co/0oRpN4Qdo0
— Christopher Miller (@ChristopherJM) May 27, 2014
This is what’s left of Donetsk, Ukraine, hockey arena after armed men broke in & set it afire. http://t.co/XH08UPcVlo pic.twitter.com/k9hrEm1zW2
— Jim Roberts (@nycjim) May 27, 2014
Some photos from yesterday's fighting at Donetsk Airport. http://t.co/nBsnSOUSzn
— Shaun Walker (@shaunwalker7) May 27, 2014