WASHINGTON (KTEN) -- Former Texas Rep. John Ratcliffe was sworn in Tuesday as the Director of National Intelligence.

Ratcliffe, a Republican who served the 4th District, was confirmed by the U.S. Senate last Thursday in a party-line vote. Democrats refused to support the nomination over fears that he will politicize the intelligence community's work under President Donald Trump.

Ratcliffe will take over the agency at a tumultuous time. The nation faces threats from Iran and North Korea, Russian disinformation campaigns to interfere in the U.S. elections and tensions with China over rising competition and the spread of the coronavirus. At the same time, Trump has viewed the intelligence agencies with distrust and ousted or fired multiple officials.

“Confronted with a diverse and challenging global threat landscape, my highest priority as Director of National Intelligence is to provide timely, accurate, and objective intelligence to inform the President and policymakers, and ultimately to keep all Americans safe," Ratcliffe said at his swearing-in on Tuesday. "I look forward to leading this team of the world's most talented and effective intelligence professionals with the highest standards of public service and with fidelity to the Constitution and the rule of law."

The Texas Republican seemed unlikely to get the position when Trump in February announced plans to nominate him, as he had already been selected for the job last year and then withdrew after Republicans questioned his experience. But senators warmed to him as they grew concerned about the upheaval in the intelligence community and wanted a permanent, confirmed director.

Ratcliffe will replace Richard Grenell, the current acting director who has overseen some of the personnel changes. Grenell, the U.S. ambassador to Germany, has a thin intelligence background and is seen as a loyalist to Trump.

Ratcliffe previously served as the U.S. Attorney for the Eastern District of Texas, a position that will soon be vacant after former Grayson County District Attorney Joseph Brown announced his resignation on Tuesday.

The 4th District Congressional seat remains vacant.

CNN Wire contributed to this report.