LONDON (AP) — Britain has promised Poland strong business, diplomatic and cultural ties — as well as a deployment of troops near the Russian border — as London tries to build goodwill with European allies before European Union exit talks.

Prime Minister Theresa May had warm words for Polish Prime Minister Beata Szydlo after the pair met at 10 Downing St. on Monday. But she didn't offer an outright guarantee that almost 1 million Poles living in Britain will be able to stay once the U.K. has left the 28-nation bloc.

May reiterated her intention to give Poles and other EU nationals the right to remain — as long as Britons in other EU nations get the same guarantee.

"I hope we can reach an early agreement on this issue," May told reporters.

Poland is considered one of Britain's strongest allies in the EU, and May said before Monday's meeting that she hoped Brexit would "serve as a catalyst to strengthen" the relationship.

Szydlo said Brexit was "not the most important topic" at the talks, which focused on the economy, trade, science, culture and defense.

Britain confirmed it would send 150 troops to Poland in April as part of a NATO deployment to provide reassurance amid concerns about Russian military activities.

"We must recognize increasing Russian assertiveness, and I think it's important we work together to deal with that," May said.

The two leaders said they agreed on the importance of maintaining sanctions against Russia for what Szydlo called its "act of aggression against Ukraine."

Poles, who have moved to Britain in the hundreds of thousands since Poland joined the EU in 2004, became a focal point for anti-EU sentiment during the EU referendum campaign. There was a spike in hate crimes targeting eastern Europeans after the June 23 vote.

Szydlo said Britain and Poland would continue "working together in order to make sure that the Polish community in the U.K. is safe."

Associated Press writer Monika Scislowska in Warsaw contributed to this story.