COLOGNE, Germany — Britain should be allowed easy access to European Union defense funds even as a nonmember, according to German Defence Minister Ursula von der Leyen.

“It is very important that within PESCO, third-party states who we want to keep at our side have the ability to participate in projects in an uncomplicated way,” von der Leyen said Friday near the town of Minden, as she hosted her U.K. counterpart Gavin Williamson for his inaugural visit to Germany.

Participating in EU military missions “certainly also” should remain a possibility for countries outside the union, she added.

PESCO refers to the European Union's mechanism for a permanent structured cooperation on defense. The initiative has its own funding stream meant to develop military capabilities as a collective. It constitutes the cornerstone of what leaders here have praised as the continent's emerging voice in military matters against a resurgent Russia to the east.

European leaders next month are expected to hammer out a path allowing third-party states to engage with the EU through the PESCO framework. The decision will be closely watched, as it offers a glimpse of how the entire defense dimension with a critical ally will fare after Brexit, scheduled to occur on March 29, 2019.

Speaking alongside von der Leyen, Williamson said NATO would remain the most important security alliance for the West. But he also said Britain remains interested in EU affairs.

“There is so much that Britain does in terms of European defense that it is actually important to be able to plug into the European Union,” Williamson said. “And that’s something we hope to be able to get agreement on.”

The two defense ministers observed joint troop demonstrations at the German military base Minden and at the nearby town of Augustdorf, where British Army forces are stationed at the Sennelager barracks and training installation.

They also signed a joint declaration to deepen bilateral defense ties. The pact includes greater cooperation on aircrew training — both nations operate the Eurofighter, Typhoon and Tornado warplanes — and common plans to expand amphibious bridge-laying capabilities, according to von der Leyen.