The newly elected Ukrainian leader announced plans to sign the pact in Brussels on 27 June. He made the statement during a parliamentary vote of confidence for Ukraine's new foreign minister Pavlo Klimkin on 19 June.
Poroshenko was elected president in May on a pro-EU platform following six months of political turmoil. He told reporters that the move will shift Ukraine away from Moscow's influence and ruled out joining a Russia-led customs union.
"That's what we have been waiting so long for, what millions of Ukrainians wanted to achieve and what they've been fighting for over the last six months. And I am sure it will take place next week," said Poroshenko.
"[The EU association agreement is] what we have been waiting so long for, what millions of Ukrainians wanted to achieve and what they've been fighting for over the last six months" - Petro Poroshenko
The decision by former president Viktor Yanukovych to abandon the EU-Ukraine association agreement last November in favour of closer ties with Moscow ignited several months of mass protests in the country's Maidan Square and led to him abandoning his post.
Since Yanukovych fled the Ukrainian capital, Russia has annexed Crimea, with Moscow accused of fuelling rebellion in the east of the country.
His departure paved the way for the instalment of a pro-EU caretaker government whose validity was rejected by Russia, leading to separatists in eastern Ukraine claiming independence from Kyiv.
According to a UN estimate released this week, at least 356 people, including 257 civilians, have been killed in eastern Ukraine since 7 May.
Interim Ukrainian prime minister Arseniy Yatsenyuk signed the political section of the EU association agreement in March 2014.
"Some economic problems may appear for us, and we will be unable to keep a zero import duty [on Ukrainian exports] for certain" - Vladimir Putin
And now, the economic section will be signed next week. It requires Ukraine to open up its markets to the EU's free trade zone; setting the condition that Kyiv should lift its barriers to EU imports.
At the moment, Ukraine has restrictions on EU products to protect its farmers and steel mills in the industrial east of the country from direct EU competition.
However, Russian president Vladimir Putin warned that Ukrainian exports to Russia will no longer be zero-rated should Kyiv sign the economic part of a free trade agreement with the EU.
"Some economic problems may appear for us, and we will be unable to keep a zero import duty for certain," said the Russian leader.