BRUSSELS — The European Union pledged on Tuesday to push ahead with work on a free trade agreement with Ukraine and called on Russia to respect the peace agreement aimed at ending six years of conflict in eastern Ukraine.

After talks in Brussels with Ukrainian President Volodymyr Zelenskiy, European Council President Charles Michel, who represents the bloc's 27 national leaders, said that "the EU is and will remain Ukraine's biggest and most reliable partner."

"We want to deepen our cooperation with Ukraine even further," he told reporters.

The EU has given about 15 billion euros ($17.7 billion) in support to Ukraine since Russia annexed its Crimean Peninsula in 2014.

During the meeting, three new financial agreements were sealed worth around 60 million euros to support Ukraine's hard-hit eastern regions and civil society, as well as for climate sustainability.

But the EU underlined that Ukraine must do more to tackle corruption and accelerate reforms, notably on ensuring the independence of the judiciary and on limiting the influence of wealthy oligarchs.

"We are not acting just (out of) charity. We are acting because it is in our own interest to help Ukraine to develop and to be a free, prosperous and secure country. This is the purpose of our help; it is conditional to reforms," said EU foreign policy chief Josep Borrell.

In their summit joint statement, the EU and Ukraine "called on Russia to immediately stop fueling the conflict by providing financial and military support to the armed formations it backs" in the east of the country and to respect the agreement meant to underpin peace.

Brokered in 2015 by France and Germany, the Minsk peace plan aimed to resolve the conflict between Ukraine and Russia-backed separatists that flared in 2014 after Russia's annexation of Crimea and its support for the separatists. The conflict has since killed more than 14,000.

The EU imposed a raft of sanctions on Russia over the annexation and refuses to recognize Moscow's authority in Crimea. The bloc has also frozen the assets and imposed travel bans on officials in Crimea and Sevastopol accused of undermining Ukraine's sovereignty.