"Poland is giving us open and unambiguous support for Euro-Atlantic integration. We will use Poland's experience on every level, and (Poland) will offer it unselfishly," Mesic told a joint press conference.
Kwasniewski said his country could help Croatia on a political, expert and emotional level.
He said Poland was already extending determined political support, that on the expert level it could help in the creation of the right EU admission frameworks, and thirdly, share the emotional experience of negotiating the EU entry and the admission itself.
Answering a question from the press, Mesic said Croatia aimed for meeting European standards by 2007. "Our goal isn't to enter the Union only formally. We want to meet those standards on the political, social and economic level for our sake."
Kwasniewski said Poland was interested in Croatia's joining NATO as swiftly as possible. He added Poland appreciated Croatia's contribution to the anti-terror coalition, notably in Afghanistan, and understood and respected Croatia's decision not to send its troops to Iraq.
Kwasniewski also said that Poland, one of the United States' strong allies in Iraq, did not plan to withdraw its troops from there for the time being.
Mesic said Croatia was a loyal member of the anti-terror coalition. "We wish to help so the issue of terrorism can be cut off at the roots by solving the regional crises that generate it."
The two heads of state also discussed economic cooperation, concluding that it was insufficiently exploited. Last year's trade was a mere US$244 million, of which Croatian exports were $30 million.
Kwasniewski said the two countries wished to develop investment cooperation and that, although Croatia's Pliva and Podravka were major investors in Poland, there were no Polish investments in Croatia. He added attempts would be made to encourage Polish business people to correct that.
Kwasniewski said Croatia was a country of great opportunities, one of the fastest developing in Europe, a politically stable state integrating into the EU and NATO whose relations with neighbours had been settled.
Asked by the press what he would recommend to Polish business people, he said stronger cooperation and business looked very promising in the drugs industry, tourism, shipbuilding and the energy sector.
Kwasniewski also told the press he and his personal friend Mesic spent a great day in an informal meeting in Gdansk yesterday.
Commenting on the forthcoming presidential race in Croatia, he said that although it could not vote Poland wished Mesic success.