WARSAW, POLAND - Ukraine has summoned the Polish ambassador in Kyiv after Poland denied entry to a Ukrainian official in an escalation of a diplomatic spat over the two neighbors’ troubled past.

Poland’s decision to refused entry on Saturday to the head of Ukraine’s commemoration commission, Svyatoslav Sheremet, was in response to a ban imposed earlier this year by Kyiv on the exhumation of Poles killed in Ukraine during World War II, Polish state news agency PAP reported.

“The Ukrainian side has complained that Mr. Sheremet was not allowed into Poland,” Poland’s ambassador to Kyiv, Jan Pieklo, told PAP after the meeting with Ukrainian authorities.

“I have been also informed that this is a problem that concerns the restarting of exhumations because Sheremet is the person responsible for this,” Pieklo said, adding that both sides had agreed that the exhumations should be restarted.

In an apparent effort to mend ties, representatives of the Polish and Ukrainian presidents said on Friday that they “reconfirmed their commitment to strengthening the strategic partnership.”

“The parties agreed that the ban on the search and exhumation works in Ukraine should be lifted,” the statement published Friday said.

The denial of entry to Sheremet came after the Polish foreign minister said earlier in November that Poland would bar Ukrainians with “anti-Polish views.”

Poland last year passed a resolution that declared the World War II-era killing of about 100,000 Polish men, women and children by units in the Ukrainian Insurgent Army (UPA) “genocide.”

Ukraine rejects that label, saying the killings were a result of bilateral hostilities.