Portland Mayor Ted Wheeler is sending the city's police force out to Saturday's protest with words of encouragement following several tense exchanges with the police union in recent weeks.

Wheeler wrote an open letter Friday expressing his trust in and gratitude for the Portland Police Bureau as officers and command staff prepare for right-wing Patriot Prayer and left-wing counter-protesters to hold dueling protests Saturday. Such encounters normally lead to violence.

"Serving as a police officer is undoubtedly one of the most challenging, risky and demanding jobs in our city," Wheeler wrote.

This letter comes a day after Daryl Turner, president of Portland's police union, said the mayor has "failed miserably" as police commissioner, citing perceived "personal, political bias" as having inappropriate influence over Wheeler's command of the bureau.

Turner's was the latest in a series of statements made in opposition to Wheeler's leadership of the police. Through their union, officers have been highly critical of Wheeler's policies regarding homeless people, with Turner saying the mayor allowed the city to become "a cesspool."

An attorney representing employees of Immigration and Customs Enforcement on Monday accused Wheeler of hindering law enforcement services to ICE employees during a 38-day-long occupation. Wheeler earlier tweeted that he did not want Portland police "engaged in the conflict."

The attorney's letter claimed policies put in place by Wheeler created "a zone of terror and lawlessness" which resulted in threats of physical violence and harassment toward ICE employees.

The mayor denied such policy claims, calling the assertion "inaccurate and inflammatory" in a letter Tuesday.

Wheeler's letter Friday was remarkably affable.

" ... As always, you will rely on the strong leadership of your command staff, your training and your good judgment," Wheeler wrote Friday.

Wheeler in the letter said he wants to make clear his support for the bureau, citing the addition of 52 officers to the bureau, strengthened funding for the Service Coordination Team and increased support for Behavioral Health Unit and other developments.

"Chief Outlaw has exceeded my expectations," he also said of Danielle Outlaw, whom he named police chief one year ago.

Wheeler also thanked the non-sworn staff, calling them "the backbone of our operations," a group whose work he said is often overlooked.

"I know that this is a particularly challenging situation, and I want you to know that I have complete trust in your ability to manage it," Wheeler said in reference to Saturday's demonstrations.

Here is the full statement from Wheeler:

It is an honor to serve as your Police Commissioner.

Serving as a police officer is undoubtedly one of the most challenging, risky and demanding jobs in our city. Once again, you will be called upon to secure the safety of our residents during this weekend's planned demonstrations. I know that this is a particularly challenging situation, and I want you to know that I have complete trust in your ability to manage it. As always, you will rely on the strong leadership of your command staff, your training and your good judgement.

It is unfortunate that there are conflicting stories around my support for the Portland Police Bureau at such a critical time. I believe it is my duty to clarify a couple of points.

While you were doing your part to protect and serve the community, I was pleased to champion an increase the number of sworn police officer positions by 52, strengthen funding for the Service Coordination Team, increase support for the Behavioral Health Unit, fund new trainers and data analysts, and work with local business leaders to support increased revenues for critical services, including public safety enhancements. I will continue to support you as your Mayor.

I also appreciate my strong relationship with the Command Staff. Chief Outlaw has exceeded my expectations – I am glad she accepted my offer to lead our team. She has proven herself to be an effective leader for the Bureau and the community, and she and her leadership team have my full confidence.

The Bureau is fortunate to also benefit from top-flight non-sworn staff. You are the backbone of our operations, and your work is often difficult and overlooked. The Bureau could not succeed without you.

Thank you again for your service to the community. I want you to know that I appreciate it.

Respectfully, Ted Wheeler.

--Anna Spoerre