While President Donald Trump said Tuesday he plans to work with Qatar to combat terrorism in the Middle East, some lawmakers pushed back on the alliance, saying the Persian Gulf country may still be aiding extremist groups.

Since last June, Qatar been under a diplomatic embargo by regional U.S. allies including Saudi Arabia, Egypt and the United Arab Emirates amid accusations of its ties to “terrorist organizations.” Qatar has denied the allegations.

Rep. Brad Sherman said the United States should look more closely into any links Qatar might have to radical groups. 

“We should certainly have meetings, even with people we disagree with,” the California Democrat said in an email. “Qatar certainly has continuing contact with Hamas and we are reviewing whether they are helping to finance Hamas.”

The U.S. government considers Hamas, the Palestinian Islamic political party, a terrorist organization.

Trump on Tuesday met with Qatari ruler Sheikh Tamim bin Hamad Al Thani at the White House, where the president praised his country for working with the U.S. to stop “the funding of terrorism.”

“Tamim and I have been working for a number of years now — actually, even before the fact — on terrorism,” Trump said. “We’re making sure that terrorism funding is stopped in the countries that we are really related to.”

Saudi Arabia, the U.A.E., Bahrain and Egypt, which imposed the embargo on Qatar, accuse the country of spreading extremism and being too close to Iran. Qatar has repeatedly denied having ties to terrorist groups, but Trump originally supported the Saudi- and Emirati-led blockade.

The U.S. has since pushed to resolve the standoff, and on Monday the State Department approved a $300 million sale of guided missiles to Qatar after Sheikh Tamim met with Defense Secretary Jim Mattis.

Some lawmakers have moved to take action aimed at Qatar in the past year. Last May, a bipartisan group of House members, including Sherman, introduced legislation calling for sanctions on “foreign persons, agencies and governments that assist Hamas, the Palestinian Islamic Jihad or their affiliates.”

The bill’s text accused Qatar of hosting multiple Hamas leaders, including exiled chief Khaled Mashal, who has been interviewed regularly on the Qatar-based Al-Jazeera network. It also said Qatar gave Hamas “significant financial and military support.”

Sherman said the lawmakers are hoping to “fine-tune” the bill, but plan to move forward with the legislation. He is also seeking a classified briefing on any Qatari-Hamas activity to ensure the country is not giving the Islamist group financial support.

Sheikh Tamim reiterated Tuesday that his country does not support extremists groups.

“We do not and we will not tolerate people who fund terrorism,” he said.

A longtime ally of the United States, Qatar still hosts an active U.S. military base near its capital, Doha.