WASHINGTON, June 27 (Xinhua) -- U.S. President Donald Trump said on Wednesday that he will probably meet Russian President Vladimir Putin during his scheduled trip to Europe in July.

"We'll probably be meeting sometime around my trip to Europe," Trump told reporters at the White House during his meeting with visiting Portuguese President Marcelo Rebelo de Sousa.

The location could be in Helsinki or Vienna.

Trump also said the talks will focus on Syria and Ukraine.

Kremlin said earlier on Wednesday that the two presidents are expected to meet in a third country, with the date and venue to be announced on Thursday.

The remark came after Putin's closed-door meeting with visiting U.S. National Security Advisor John Bolton in Moscow.

Bolton's visit reflected "the continued desire of the Trump administration to improve relations with Russia," Dan Mahaffee, senior vice president and director of policy at the Center for the Study of the Presidency and Congress, told Xinhua.

Mahaffee said Trump, emboldened by his "negotiating successes," felt that he can move forward on meetings with Russia.

Trump will attend the NATO Summit in Brussels on July 11-12 and then visit Britain.

He last met with Putin in Vietnam on the sidelines of an Asia-Pacific summit in November.

The expected Trump-Putin meeting will take place amid strained bilateral relations due to Russia's alleged meddling in the 2016 U.S. presidential elections, among other thorny issues.