President Joe Biden said Tuesday that U.S. and its allies are on track to complete evacuations from Afghanistan by his Aug. 31 deadline, with thousands of U.S. citizens, Afghans and others being flown out of the country each day.

Im determined to ensure that we complete our mission, this mission, Biden said in public remarks from the White House. Im also mindful of the increasing risks.

The president said the U.S. had helped evacuate 70,700 people since Aug. 14, including about 12,000 in the last 12 hours alone.

Biden met with G-7 leaders earlier Tuesday and discussed U.S. troops withdrawal from Afghanistan. He is under increasing pressure from U.S. lawmakers, along with refugee advocates, to push off the deadline in order to ensure vulnerable people are able to get out of the Taliban-controlled country.

But Biden suggested he wont budge, warning that staying longer could be dangerous. Every day the U.S. remains in the country increases the risk of attacks on American forces by terrorist groups and the Taliban, which has said it will not accept an extension.

Biden cautioned that completing evacuations by Aug. 31 is contingent on the Taliban allowing access to the Kabul airport, where flights are taking off regularly to transport vulnerable people to safety. Biden said he had asked the Pentagon and State Department to develop contingency plans in case the deadline had to be extended.

Lawmakers from both parties including Senate Minority Leader Mitch McConnell (R-Ky.) earlier Tuesday along with refugee advocates argued that meeting that deadline is less important than getting Americans and Afghan civilians out of the Taliban-controlled nation.

Evacuations are ramping up. The U.S. and its allies flew about 21,600 people out of the country from Monday to early Tuesday, the largest number in a 24-hour period yet. Evacuation flights are leaving the Kabul airport every 45 minutes, according to the Pentagon.

But there are many more people to evacuate, including those who worked with U.S. troops and now are seeking protection under the Special Immigrant Visa, or SIV, program.

As of last week, more than 17,000 Afghan nationals and about 53,000 of their family members were waiting to be approved under the SIV program. The U.S. welcomed only about 2,300 people under the program from January to July, and another 2,000 last week.

Refugee advocates have been critical of Bidens approach to evacuating Afghan allies and civilians, and particularly of the administrations failure to grant more special immigrant visas sooner. Some called on Biden to continue work in Afghanistan until the evacuation is done, rather than sticking to the Aug. 31 deadline.

President Biden must continue the evacuation until all U.S. citizens, Afghan allies, and other extremely vulnerable Afghans have reached safety, Krish OMara Vignarajah, president and CEO of the refugee resettlement group Lutheran Immigration and Refugee Service, said in a statement on Tuesday. We swore a sacred oath to protect them we cannot break it in the eleventh hour.

The White House has noted that former President Donald Trump decimated the refugee resettlement pipeline, making it difficult to ramp up quickly. Still, many advocates have questioned why Biden didnt act more quickly to resettle Afghan allies.

They seem to be afraid. They seem to be operating out of fear that being a bit bolder on issues with refugees, asylees and migrants will somehow cost them politically, Julin Castro, a former housing secretary who pushed to expand refugee resettlement during his presidential bid, told HuffPost last week . This is an area where theres growing disappointment and impatience and the stirrings of real anger towards the administration.

Biden said the U.S. will be a leader in efforts to take in refugees and encourage allies to do the same. Anyone resettled in the U.S. will be fully vetted, he said.

We must all work together to resettle thousands of Afghans who ultimately qualify for refugee status, Biden said. The United States will do our part, and we are already working closely with refugee organizations to rebuild a system that was purposefully destroyed by my predecessor.