Irish Taoiseach Leo Varadkar | Jonathan Nackstrand/AFP via Getty Images Irish PM wants to avoid no deal, but ‘not at any cost’ ‘I don’t play dirty and I don’t think most EU leaders do either,’ Leo Varadkar says.

Irish Prime Minister Leo Varadkar will "certainly work until the very last moment" to ensure the U.K. gets a Brexit deal with the EU, but "it’s going to be very difficult to secure an agreement by next week," he said.

Speaking to Irish broadcaster RTÉ on Tuesday after a 45-minute phone call with British Prime Minister Boris Johnson, Varadkar said Dublin wants an agreement, "but not at any cost.”

Varadkar acknowledged the debate about Brexit is becoming more toxic "in some quarters," but mostly not from the EU. "I don't play dirty and I don’t think most EU leaders do either," he said.

The comments came after a hostile U.K. government briefing of a Tuesday phone call between Johnson and German Chancellor Angela Merkel.

Varadkar said there are still two significant issues with Johnson's new Brexit proposals: the customs elements of the plan — which envisions checks on goods away from the border — and the plan for the Northern Ireland Assembly and executive in Belfast to be able to veto the plan.

"Essentially what the U.K. has done is repudiated the deal that we negotiated in good faith with Prime Minister [Theresa] May’s government over two years and have sort of put half of that now back on the table and saying that’s a concession. Of course it isn’t,” Varadkar said.

The Irish PM is expected to meet Johnson again later this week in a last-ditch effort to avoid a no-deal Brexit.